Abstract: A spring member for use in retaining a screen within a window frame, the spring member having an elongated dome portion, an upwardly extending portion formed within the dome portion and designed to fit within a recess in a window. The spring members ideally are suited for window frames made using corner members.

Abstract: A corner bracket assembly for use in an associated frame assembly is provided. The corner bracket assembly comprises a body, a first leg and second leg. The first leg extends from the body and is adapted to be connected to a first frame member of the associated frame assembly. The second leg extends from the body in a direction approximately normal to the first leg and is adapted to be connected to a second frame member of the associate frame assembly. The corner bracket assembly further comprises a roller element rotatably mounted within one of at least two axially spaced positions in at least one of the body, the first leg, and the second leg. The roller element protrudes outward a selected distance relative to at least one of the body, the first leg, and the second leg.

Abstract: A frame for a ventilation screen-frame assembly includes a body having a mounting surface for receiving ventilation screen material. In one example, the body has at least three V-shaped cuts partially through it. Each V-shaped cut leaves an edge of the body uncut. The body is folded about each uncut edge so that the ends of the body meet at a corner. Each V-shaped cut subtends an angle &thgr; that is slightly less than 90 degrees, so that the folded corners are in compression. The assembly further includes a single corner key for joining the ends of the body into a closed frame. A reinforcement clip may optionally be provided in each folded corner.

Abstract: An apparatus and method for a window shutter system are disclosed. A window shutter system (100) is disclosed that includes a plurality of shutter frames (106, 108). Each shutter frame (106, 108) includes a plurality of elongate members (126, 130). Each of these elongate members (126, 130) has two ends, and each end has a receiver (204, 208). The shutter frames (106, 108) also include a plurality of couplers (128, 120, 132, 140). Each coupler (128, 120, 132, 140) has at least two extensions (202, 206) for connecting adjacent elongate members. These extensions (202, 206) are adapted to interlock with the receiver (204, 208) of an associated elongate member (126, 130) such that the elongate members (126, 130) and the couplers (128, 120, 132, 140) cannot rotate relative to one another. In addition to the shutter frames (106, 108), the shutter system (100) also includes at least one hinge (112, 114) that may be used to couple one of the elongate members (126, 130) to a window frame (110).

Abstract: A corner bracket assembly for use in an associated frame assembly is provided. The corner bracket assembly comprises a body, a first leg and second leg. The first leg extends from the body and is adapted to be connected to a first frame member of the associated frame assembly. The second leg extends from the body in a direction approximately normal to the first leg and is adapted to be connected to a second frame member of the associate frame assembly. The corner bracket assembly further comprises a roller element rotatably mounted within one of at least two axially spaced positions in at least one of the body, the first leg, and the second leg. The roller element protrudes outward a selected distance relative to at least one of the body, the first leg, and the second leg.

Abstract: An improved screen printing frame connector is presented, the connector possessing flanges for easy insertion of frame side members and also providing large drainage holes to permit easy drying of the frame after washing.

Abstract: The present invention presents a stretching frame for fabric materials such as an artist's canvas which can be easily assembled and disassembled, while providing superior rigidity. Unique inner frame members interlock orthogonally along the inner length of outer frame member to prevent the tension of the canvas from deflecting the frame inwardly. Half lapped joints at the corners of the inner frame members provide additional strength for the frame and the ability to adjust the tautness of the canvas in either a single direction or two directions by the insertion of wedges or turnbuckles.

Abstract: A spring member for use in retaining a screen within a window frame, the spring member having an elongated dome portion, an upwardly extending portion formed within the dome portion and designed to fit within a recess in a window. The spring members ideally are suited for window frames made using corner members.

Abstract: A screen frame is made by joining four (three or more) screen frame segments together at corners to form a generally rectangular or multi-sided screen frame. Corner joint inserts are placed within each corner of the four screen frame segments and the inserts are spot welded to adjoining screen frame segments to provide a sturdy and rigid screen frame. The screen frame segments are metal extrusions having two parallel flanges extending from a generally square shaped hollow body. A metal screen is secured in the screen frame by spot welding the screen between the flanges of the screen frame segment. The resulting screen frame and screen provides a long-lasting, corrosive resistant, and rigid frame and screen for positioning in window or door frames which can withstand damage from intruders, projectiles, and environmental stresses.

Abstract: A corner member for securing together the structural members forming the periphery of a screen, the corner members having a protrusion for locking the screen in place in a window to obviate the need for a separate locking device. The corner members may be formed of any color and are preferably of a plastic material which has been injection molded.

Abstract: A canvas stretching and framing device upon which canvas or other sheet material may be stretched includes fixed corner sections and straight sections. The fixed corner sections ensure the squareness and rigidity of the device while simultaneously allowing for easy adjustments in order to maintain the canvas in a taut condition over the device. The straight sections may be easily cut to any desired length, which allows for easy adjustment of the device's size. The corner sections may include a plurality of protrusions which engage a plurality of cavities formed in the straight sections in a way that forms a continuous perimeter upon which canvas may be stretched.

Abstract: A nodal assembly for connecting at least two adjacent frame members of a perimeter frame, the nodal assembly comprising a central portion having parallel first and second sides and an opening in the second side, a first leg extending from the central portion in a first direction parallel to the first side and having a cavity within it in communication with the opening, a second leg extending from the central portion in a second direction different from the first direction but also parallel to the first side, and a retainer slidably received in the cavity and movable between a retracted position substantially within the central portion and the first leg and an extended position in which the retainer extends substantially outwardly of the opening in the second side of the central portion and away from the second side.

Abstract: An apparatus and method for a window shutter system are disclosed. A window shutter system (100) is disclosed that includes a plurality of shutter frames (106, 108). Each shutter frame (106, 108) includes a plurality of elongate members (126, 130). Each of these elongate members (126, 130) has two ends, and each end has a receiver (204, 208). The shutter frames (106, 108) also include a plurality of couplers (128, 120, 132, 140). Each coupler (128, 120, 132, 140) has at least two extensions (202, 206) for connecting adjacent elongate members. These extensions (202, 206) are adapted to interlock with the receiver (204, 208) of an associated elongate member (126, 130) such that the elongate members (126, 130) and the couplers (128, 120, 132, 140) cannot rotate relative to one another. In addition to the shutter frames (106, 108), the shutter system (100) also includes at least one hinge (112, 114) that may be used to couple one of the elongate members (126, 130) to a window frame (110).

Abstract: An improved stability canvas tensioning picture frame which is formed by a plurality of abutting frame members is provided with a tapered screw and facing tapered channels in the abutting frame members, with each of the abutting frame members having a semi-circular slot adapted to receive an apertured disk in a mild interference fit, with the single apertured disk providing longitudinal and lateral stability between the abutting frame members when the screw is screwed down into the tapered channel to move the abutting members away from each other.

Abstract: An intruder resistant screen including a frame comprising elongate frame members each having a channel section engaging a respective corner stake in each end thereof. A woven wire intruder resistant mesh covering an opening enclosed by the frame. There are a plurality of clamping members that co-act with flanges projecting from the channel sections to provide leveraged clamping of the mesh against a clamping web. Respective fasteners fasten the clamping member to the clamping web.

Abstract: A window insert suitable for insertion into a conventional window insert receptacle includes a frame and a blind assembly mounted to the frame. The frame defines an opening, and is adapted for insertion into the window insert receptacle. The blind assembly can include a plurality of slats which cover the opening.

Abstract: A cover assembly for the cargo area of a vehicle includes a plurality of rails which can be attached to the walls of a truck bed and a cover having an edge which is engageable by the rails. The rails are connected together by corner members. The corner members include a locking structure which is inserted into a channel in the rails. The locking mechanism of the corner members engages slots in the rails and secures the rails together. The rails include different structures which engage fasteners on the edges of the cover.

Abstract: A window cornice assembly is disclosed. The window cornice assembly may comprise a front section and two side sections upon which fabric may be arranged. Corner pieces may be mounted on the front and side sections. Fabric may be arranged and secured on the front and/or side sections by clips that retain the fabric taut and over the front face thereof. The clips can be attached to each other directly by an elastic cord or band, or attached to the rear face of the front section directly so that the fabric is tightly pulled over the front face of the front section. The elastic cord or band imparts a desired amount of elasticity to the fabric. The window cornice assembly may have one or more elongated channel-shaped support strips arranged on a front section to provide additional rigidity thereto.

Abstract: This fabric stretching system for artists' canvases, silk screens, and the like, utilizes extruded, specially profiled, wood-like material in place of conventional wooden bars to form a frame on which canvas is stretched. Each corner of the frame is joined by two identical corner braces, which mate to profiled features of the frame and lock the bars rigidly together. The extruded frame material, which is made from recycled wood and other organic materials held in a plastic binder, maintains the weight and feel of traditional wooden frames but is free of many of the disadvantages of wood. The material as extruded is ready for use. It needs only to be cut to the desired length, an operation which can be done with a simple miter saw. Two braces are used in each corner, the second containing adjustment screws for tensioning. This arrangement makes for simple assembly and assures a rock solid frame which can be adjusted to provide additional tension on the canvas at time of assembly or at any future time.

Abstract: A screen frame formed from a metal sheet in a single unit folds and locks on V-cuts in a tube by a locking mechanism that is configured to engage in crossed directions by the folding.

Abstract: A connector assembly for connecting and locking tubular elements in preselected angular relationships. The connector assembly includes a pair of clevis having tube engaging elements at one end and three clevis rings at the other. The clevis rings of each clevis are interengaged and define a bore. The bore has a plurality of grooves therein. Locking elements, including a locking pin and a locking plug are inserted in the bore. The locking pin and locking plug each have a pair of opposed raised ribs and a pair of opposed resilient locking arms that engage the grooves in the bore. Detents on the ends of the resilient arms engage a space between the interengaged clevis rings to secure the locking elements in place. The tubular elements can be interconnected in a system of frames to suspend function and decorative panels.

Abstract: An apparatus and method for forming a metal frame for an article of furniture which includes a base portion made up of four peripheral edge members disposed in a rectangular arrangement. The frame also includes a back frame portion and two arm frame portions each having at least three peripheral edge members which are interconnected to each other at right angles. Each of the base frame portion, the back frame portion and the two arm frame portions includes at least one strip of longitudinally corrugated metallic sheet material which has at least one generally U-shaped longitudinally extending rib therein. Bend locations are provided for bending the strip of longitudinally corrugated metallic sheet material at right angles. A combination of corresponding strips of velcro, hooks and loops are used in conjunction with J-strips to removably attach upholstery to the frame.

Abstract: Members to be coupled have hollow coupling parts at opposite side surfaces, a coupling member has, at opposite ends, press-fitting parts which are press-fitted in the hollow coupling parts, and angle shape concavities and convexities having crests which are corrupted upon press-fitting are formed on at least either one of an inner peripheral surface of the hollow coupling part and an outer peripheral surface of the press-fitting part. When the opposite end parts of the coupling members are press-fitted in the hollow coupling parts of the members to be coupled, the crests of concave parts of the angle shape concavities and convexities are corrupted by the opposed surface so as to be made into close contact with and firmly coupled to the associated surface, thereby it is possible to surely couple a pair of members to be coupled with a simple work.

Abstract: The present invention provides a window screen having operators that secure the window screen relative to a window frame. A pair of single rail operators releasably secure the upper end of the screen relative to the upper end of the window frame. A pair of double rail operators releasably secure the lower end and sides of the screen relative to the lower end and sides of the window frame.

Abstract: A frame member is extruded from a composite material including plastic and wood fiber. A plastic end cap is sonically welded to a cut end of the frame member despite the presence of wood fiber at the interface.

Abstract: A light weight, upholstered panel for use in modular and free standing office landscaping systems. The panels form free standing partitions which can be rearranged and assembled into an office system. Panels can be interconnected and positioned over a range of angles relative to adjacent panels. The panel core is composed of a light weight composite structural material with perimeter frame members along each edge. Each frame member has the same cross-section along its length. The horizontal perimeter horizontal frame members are inter-connected with the vertical frame members by corner connectors. The corner connectors have protrusions which engage hollow cavities in the ends of the frame members. The perimeter frame acts to transfer loads imposed on the panel to the structural core. The perimeter frame members incorporate formations to secure the panel fabric, trim and the inter-panel connection system in place and provide recesses for fasteners and support hardware.

Abstract: A frame construct for holding at least one planar mesh or membrane in set-apart relationship from a structural port(a1). Individual frame pieces, top, bottom and sides, are cut to desired lengths and joined to form a glazable frame. Shapes other than of rectangular geometry are obtainable through use of variously angled joiners. Peripheral grooving on both frame faces is receptive of a spline that secures the planar mesh or membrane to the frame, which is then dogged to or otherwise secured in place on/over an opening such as a window, door or the like. Corner elements of the construct also serve as joiners; and, one spline may also comprise a weather strip.

Abstract: A connector assembly for connecting and locking tubular elements in preselected angular relationships. The connector assembly includes a pair of clevis having tube engaging elements at one end and three clevis rings at the other. The clevis rings of each clevis are interengaged and define a bore. The bore has a plurality of grooves therein. Locking elements, including a locking pin and a locking plug are inserted in the bore. The locking pin and locking plug each have a pair of opposed raised ribs and a pair of opposed resilient locking arms that engage the grooves in the bore. Detents on the ends of the resilient arms engage a space between the interengaged clevis rings to secure the locking elements in place. The tubular elements can be interconnected in a system of frames to suspend function and decorative panels.

Abstract: An apparatus and method for tensioning a screen on a roller frame are disclosed. The apparatus includes a fixture having a plurality of clamp mechanisms for releasably securing the frame to define a screen tensioning plane, and at least one double-headed wrench for applying torque to the frame rollers adjacent opposite ends thereof. Each torque wrench includes a lever arm which is operable by torso engagement, thereby freeing a user's hands for manually unlocking and locking a selected roller for rotation.

Abstract: A frame assembly for doors, windows and the like includes a fastening element consisting of a longitudinal connecting portion and a transverse clamping portion, a first frame provided with a plurality of locking holes and a second frame provided with two fastening holes. The connecting portion has a side plate extending substantially perpendicular to either lateral side thereof and is provided with a plurality of threaded holes at an upper portion thereof for matching the locking holes. The clamping portion consists of a clamp plate punched and bent from a middle portion of the connecting portion and a grip plate in a relative clamping relationship with the clamp plate; the grip plate being provided with two projecting hook pieces for matching the fastening holes. The connecting portion may be inserted into the first frame so that they may be locked firmly and conveniently by screws.

Abstract: The present invention provides a window screen having operators that secure the window screen relative to a window frame. A pair of single rail operators releasably secure the upper end of the screen relative to the upper end of the window frame. A pair of double rail operators releasably secure the lower end and sides of the screen relative to the lower end and sides of the window frame.

Abstract: A closure assembly is provided assembled from framing sections being fiberglass pultrusions having thin walls, sufficiently thin so as to require reinforcing of the pultrusion proximate the ends and at predetermined positions to allow for (i)joining adjacent pultrusions together and (ii) assembling hardware to the pultrusion, (iii) mounting the pultrusions when assembled in an opening.

Abstract: A stretcher bar frame for artists' backing material and kit to make same. Lengths of lumber rails of conveniently available standard sizes, such as 1".times.3" and 2".times.4", can be used with a plurality of molded corner bracket units, each having two channels sized to receive, and completely enclose the outer side walls of, the lumber rails. In a first embodiment, the corner brackets units have a bead region extending around their upper and outer perimeter. In other embodiments, separate bead members are provided, which can be cut to a desired length, for fixable attachment to the lumber rails to form a continuous bead region around the perimeter of the stretcher bar frame, such that when the backing material is stretched over the front of the stretcher bar, it rides on the outer perimeter bead, and not on the stretcher bar frame.

Abstract: A window screen frame includes at least one corner key which has, as an integral component, a stop that prevents the screen frame from penetrating too deeply into tracks in a window jamb. The corner key is preferably molded plastic and includes two legs, each supporting a raised member. The legs meet at an angle to form the corner and the raised members form the stop. In a preferred embodiment, the raised members meet at the corner to form a corner-shaped stop. One or more of the corner keys may also include integral handles, for moving the frame along tracks in the window jamb. The corner keys may further include retreats for receiving locking pins. The locking pins extend through the window frame and into the retreats to retain the window screen frame in a desired position. A window screen frame including at least one of these corner keys also includes frame segments that mate with the corner key.

Abstract: A rectangular cloth fixing frame for use in painting or embroidery. The frame including a plurality of frame portions. Each frame portion including a surface projection near an outer periphery of a front surface thereof and a fixing fitting groove on the outer peripheral end surface. Corner members connect the frame portions so as to form the cloth fixing frame. A cloth such as a canvas of a desired shape is spread over the rectangular frame, a plurality of fixing elements are driven through the canvas and into the fixing fitting groove to thereby fix the canvas to the rectangular frame under tension.

Abstract: An expandable frame assembly is provided for supporting and stretching a fabric which includes a plurality of frame portions together defining the periphery of the frame assembly and each having opposed ends and an interior bore extending therethrough, and a plurality of connective expansion members each including first and second extension portions. Each extension portion is slidably mounted within an interior bore of one of the frame portions and has a planar contact surface thereon. An adjustable bearing mechanism is mounted in each end of the plurality of frame portions. Each bearing mechanism has a spherical bearing surface for engaging the planar contact surface of the expansion member proximate thereto to exert a bearing force thereupon. Cladding strips are provided on an outer surface portion of each frame portion for securing a piece of fabric to the frame assembly.

Abstract: A corner assembly, for holding a screen frame, is provided in which the corner assembly has a pair of arms disposed to be connected to frame side members, preferably by being telescopically received therein, for installation inside a fixed frame at the periphery of a window. Each corner assembly includes a slide member carried in a slideway, which slide member carries a retaining protrusion extending therefrom, and with the slide member having a manually engageable, movable button, movable longitudinally, to move the slide member and its protruding button between two positions, one position of which is an extended position for the retaining protrusion, and another position of which is a retracted position therefor. In the extended position of the retaining protrusion, the protrusion is adapted to engage within a recess of a fixed frame member of a window.

Abstract: Corner members and frame members forming an assembly is provided, for holding a screen or the like, in which the corner members have arms disposed to be connected to frame members, preferably by being telescopically received therein, for facilitating retaining the frame assembly, which is a removable assembly, inside a fixed frame of a window. Upper corner members of a moveable frame have a U-shaped attachment means formed by an upwardly projecting flange and tab forming U-shaped channels. The top of the frame having the U-shaped attachment means is inserted at an angle into a downwardly projecting lip means on a fixed frame such that the U-shaped attachment means loosely embraces the lip means. The moveable frame is rotated until the U-shaped attachment means fully embraces the lip means, the moveable frame is flush with fixed frame, and the moveable frame is locked into position against the fixed frame with retaining mechanisms on the remaining two corners of the moveable frame.

Abstract: A bracket for a screen frame corner has a bolt for latching the frame in a window frame, and intersecting tracks for the bolt, one track in each leg, from which the bolt may be extended from the bracket. Bifurcated radial spring legs on the bolt grip the track. The bolt may be inserted in a track by a front opening in bracket, and a frame bar mounted on the leg prevents removal of the bolt from the track. The corner bracket and the bolt with spring are each, molded single elements.

Abstract: A corner assembly and frame comprising such assembly is provided, for holding a screen or the like, in which the corner assembly has a pair of arms disposed to be connected to frame side members, preferably by being telescopically received therein, with a frame generally having such corner assemblies at corners thereof, for facilitating retaining the frame assembly, which is a removable assembly, inside a fixed frame at the periphery of a window. Each corner assembly includes a slide member carried in a slideway, which slide member carries a retaining protrusion extending therefrom, and with the slide member having a manually engageable button, movable button, movable longitudinally, to move the slide member and its protruding button between two positions, one position of which is an extended position for the retaining protrusion, and another position of which is a retracted position therefor.

Abstract: A U-shaped corner clip for use with mitered corners of first and second hollow frame members. One leg of the clip has a hook to engage an opening in the outer edge of a first frame member. The other leg is insertable through an opening in the second frame member but has a length such that it passes from the interior of the second frame member into the interior of the first frame member and there resiliently bears on the inner face of the inner edge of the other frame member. Thus, any force tending to rotate the frame members apart in a direction to increase the angle therebetween is resisted by the action of the second leg member on the first frame member. The clip also resists any force tending to move the frame members linerally away from each other in any direction.

Abstract: A corner bracket is provided for use with a fabric supporting track assembly of a type adapted for installation of a fabric wall covering onto a wall. The corner bracket has a generally triangular configuration defining a generally L-shaped corner piece hingedly connected to a bracket base adapted for fixed attachment to the wall. The bracket base supports the corner piece within a corner of the wall, in alignment with horizontal and vertical components of the track assembly. The corner piece is hingedly movable between an easily accessed first position pivoted away from the wall corner for facilitated attachment of the fabric wall covering thereto, and a second position pressed into the wall corner for snap-fit interlock with the track components.

Abstract: The partition wall units include panels with mitered tubular frame strips, posts, raceways which also can be adapted for baseboards, and covering edge strips. Most of these units include a groove along an outer edge into which are removably mounted interlocking or interhooking key members having uniform C-shaped cross-sections. These C-shaped cross-section key members on adjacent edges slideably engage each other to form cylindrical apertures between the two interhooked C's. Self-tapping screws are then screwed into these cylindrical apertures near the ends of the adjacent strip for locking the two units together. The substantially rectangular tubular frame strips around the panels have mitered joints which are connected by a pair of longitudinally complementary angle blocks with complementary grooves along their legs between their abutting surfaces.

Abstract: An arcuately adjustable roller and corner key for sliding screen doors comprises a corner key having a hollow portion to receive a roller which is mounted on an axle. A pair of aligned arcuate slots in spaced sides of said hollow portion allow adjustable movement of said roller so that it can be used to form a right or left corner connector.

Abstract: A tensioning apparatus for stretching screen fabric or other membrane comprising an expandable tensioning frame to operatively support the screen fabric or other membrane cooperatively formed by a plurality of frame members and a corresponding plurality of corner members, and at least one expansion or tensioning tool to selectively expand the expandable tensioning frame to stretch the screen fabric or other membrane thereon.

Abstract: An expandable mesh frame is disclosed for stretching and holding a mesh fabric. The frame consists of four frame rails held together by four corner pieces. The corner pieces fit within the ends of the frame rails to construct the frame and in action with the frame rails provide a selective locking mechanism. When the frame rails are rotated in one direction, as when a fabric mesh is in place on the frame and tension is applied to the mesh, the corner pieces and the frame rail are in an alignment that allows for zero tolerance locking; however, when the frame rails are rotated in the oppposite direction, as when the frame is being disassembled, there is an excess of tolerance between the frame rail and corner pieces. The selective locking mechanism allows for a frame that is easily assembled and disassembled because of the excess tolerance when the frame is in the slack position.

Abstract: A construction for supporting a flexible sheet is disclosed which includes a U-shaped channel having opposing flanges that are adapted to receive a complimentary spline member for frictionally engaging a flexible sheet, such as window screen, between a surface of the spline member and an adjacent inner surface of one flange of the U-shaped channel. The structure has several practical applications including the construction of window screens, electrostatic air filters of the charged media type, storm windows of plastic film and the like. An improved construction for an electrostatic air filter of the charged media type is also disclosed.

Abstract: A canvas tensioning picture frame formed by a plurality of adjacent frame members having complementary first and second half-cavities formed in the ends thereof, a complementary half-bore extending between the first and second cavities, a first disk having a central aperture, a second disk having a central aperture, and a frusto-conical screw having a head sized to be received by the central aperture of the first disk. The first disk is disposed within a first cavity formed of the two first half-cavities of adjacent frame members and is manually rotatable therein. The second disk is disposed within a second cavity formed of the two second half-cavities of adjacent frame members and is firmly engaged therein to limit relative movement of adjacent frame members. The frusto-conical screw is turned by rotating the first disk and thus driving the frusto-conical screw downwardly into a bore formed by the two complimentary half-bores of adjacent frame members.

Abstract: A screen printing frame comprises four extruded plastic frame members made of a material which is recyclable and resistant to attack by the inks and solvents used in a sreen printing process. Each of the frame members include transverse reinforcing webs dividing the frame member into four elongated channels. At each mitered junction of the frame, four L-shaped plastic connectors are inserted into the contiguous channnels of contiguous frame members and adhesively secured. The screen or mesh is suitably stretched and attached to the frame by means of an adhesive.

Abstract: A tensioning stretched-canvas frame and method of use is disclosed characterized by the end portion of adjacent frame members having complementary cavities formed therein which receive a spring insert adapted to persistently force the frame members apart against the retention of canvas stretched taut thereover. The spring insert resists both rotation within the cavities and bending in the plane of the frame, accordingly making the assembled frame resistent to twisting between the frame members, distortion of the frame area, and warping of the frame's plane. A disposable bridging member may be temporarily used to maintain the frame members in abutting contact against the spring forces during initial stretching of the canvas.