Abstract: A firearm target is formed from a cardboard substrate. A first target is printed on the cardboard substrate. The cardboard substrate is folded into a box shape. The cardboard substrate is cut to form a first flap and a second flap on a first side of the cardboard substrate. The first flap and second flap include notches. The first flap and second flap are folded over with the notches interlocked. The flaps can be oriented to the bottom of the box shape and weighted for stability. A second target can be mounted to the box shape over the first target.

Abstract: A firearm target is formed from a cardboard substrate. A first target is printed on the cardboard substrate. The cardboard substrate is folded into a box shape. The cardboard substrate is cut to form a first flap and a second flap on a first side of the cardboard substrate. The first flap and second flap include notches. The first flap and second flap are folded over with the notches interlocked. The flaps can be oriented to the bottom of the box shape and weighted for stability. A second target can be mounted to the box shape over the first target.

Abstract: A firearm target is formed from a cardboard substrate. A first target is printed on the cardboard substrate. The cardboard substrate is folded into a box shape. The cardboard substrate is cut to form a first flap and a second flap on a first side of the cardboard substrate. The first flap and second flap include notches. The first flap and second flap are folded over with the notches interlocked. The flaps can be oriented to the bottom of the box shape and weighted for stability. A second target can be mounted to the box shape over the first target.

Abstract: A firearm target is formed from a cardboard substrate. A first target is printed on the cardboard substrate. The cardboard substrate is folded into a box shape. The cardboard substrate is cut to form a first flap and a second flap on a first side of the cardboard substrate. The first flap and second flap include notches. The first flap and second flap are folded over with the notches interlocked. The flaps can be oriented to the bottom of the box shape and weighted for stability. A second target can be mounted to the box shape over the first target.

Abstract: A firearm target is formed from a cardboard substrate. A first target is printed on the cardboard substrate. The cardboard substrate is folded into a box shape. The cardboard substrate is cut to form a first flap and a second flap on a first side of the cardboard substrate. The first flap and second flap include notches. The first flap and second flap are folded over with the notches interlocked. The flaps can be oriented to the bottom of the box shape and weighted for stability. A second target can be mounted to the box shape over the first target.

Abstract: Methods for producing highly pure solutions containing hydrogen fluoride, one or more salts thereof or a mixture of two or more thereof, by adding hydrogen fluoride to at least one anhydrous solvent, wherein the hydrogen fluoride is added to the anhydrous solvent or solvents in the form of a gas or as a liquified gas or as a mixture of gas and liquefied gas. High purity hydrogen fluoride and ammonium fluoride solutions produced by the inventive method are also disclosed.

Abstract: Silicon oxide etching solutions containing the product of at least one bifluoride source compound dissolved in a solvent consisting of at least one carboxylic acid, and further comprising from about 0.5 to about 3 percent by solution weight of hydrofluoric acid and from about 1 to about 5 percent by solution weight of water, wherein the total concentration of bifluoride source compound is between about 1.25 and about 5.0 moles per kilogram of solvent. Methods for selectively removing silicon oxides and metal silicates from metal surfaces are also disclosed.

Abstract: Silicon oxide etching solutions containing the product of at least one bifluoride source compound dissolved in a solvent consisting of at least one carboxylic acid, and further comprising from about 0.5 to about 3 percent by solution weight of hydrofluoric acid and from about 1 to about 5 percent by solution weight of water, wherein the total concentration of bifluoride source compound is between about 1.25 and about 5.0 moles per kilogram of solvent. Methods for selectively removing silicon oxides and metal silicates from metal surfaces are also disclosed.

Abstract: Methods for producing highly pure solutions containing hydrogen fluoride, one or more salts thereof or a mixture of two or more thereof, by adding hydrogen fluoride to at least one anhydrous solvent, wherein the hydrogen fluoride is added to the anhydrous solvent or solvents in the form of a gas or as a liquified gas or as a mixture of gas and liquefied gas. High purity hydrogen fluoride and ammonium fluoride solutions produced by the inventive method are also disclosed.

Abstract: Silicon oxide etching solutions consisting essentially of the product of at least one bifluoride source compound dissolved in a solvent consisting of about 90% to 100% by weight of at least one carboxylic acid and 0 to about 10% by weight water, wherein the total concentration of bifluoride source compound is between about 1.25 and about 5.0 moles per kilogram of solvent. Methods for selectively removing silicon oxides and metal silicates from metal surfaces are also disclosed.

Abstract: Acid etching mixtures having water content, reduced by the addition of fluorosulfonic acid. The preparation and the use of said acid etching mixtures, particularly in etching silicon, are also disclosed.

Abstract: A pressurized vessel filled with a high purity gas, said vessel having a polymeric coating covering its internal surfaces;said high purity gases selected from the group consisting of hydrogen chloride, tungsten hexafluoride, chlorine, hydrogen bromide, nitrogen trifluoride, silanes and boron trichloride;said vessel filled with gas pressure from about 200 psig to about 6,000 psig; and the material for said polymeric coating selected from the group of polyperfluoroalkoxyethylene, copolymer of ethylene and chlorotrifluoroethylene and copolymer of ethylene and tetrafluoroethylene.