Abstract: A device for assisting in the prediction of the effects that a treatment, e.g. heat-setting, will have upon a textile fabric comprises a frame which defines an interior area, securing members for securing a textile fabric to the frame so as to cover the interior area, and an angularly displacable portion of the frame to vary the dimensional characteristic of the interior area so as to impart proportional and varying tension and extension to the fabric thereby aiding in the determination of the effects of the treatment thereon over a wide range of tension and extension parameters. The fabric is positioned on the frame, the frame is angularly displaced a predetermined amount and subsequently treated, and the treatment's effect are determined.