Kindergarten or Manila Paper, 5x2 1/2 Inches.
For folds, facings and bindings.
It stretches more than material cut on the straight and can be smoothly fitted into places where straight material would have to be puckered.
To cut a true bias is to evenly sever both warp and woof threads. The width of the material is laid down the length of the selvage and the cut is made through the slanting fold. In finding a perfect square, a true bias is found in the diagonal fold. (See Fig. 16.) It may be noticed in folding that the warp threads are laid on a line with the woof threads. Any deviation from this will keep the bias from being true. In buying material on the bias, the end is folded over, the true bias found and the diagonal fold cut through. The measuring for the quantity required is then made first along one selvage and then along the other. A fold is made from one selvage to the other, and the cut is made through this fold. As greater length is obtained along the bias strip than along the selvage an equal loss will be shown in the width of the strip; about one-third is thus gained in one way and lost in the other. This must be remembered in calculating the amount of material required. Material bought on the straight will have to be folded in the same way to obtain the bias. In calculating for the strips, allow one-third more along the selvage than the required width of the bias, measure along the selvage and chalk across. If a number of strips are needed, measure four at a time and cut afterwards into halves and quarters, or fold the strips carefully one over the other and cut through the folds. The triangle left at either end may be utilized in some materials. (See bias ruffle.)
A gusset is, in its usual form, a triangle with a true bias at the base. The stretching of the bias helps to make it fit and the triangle gores are at the end of the seam.
Care must be taken in piecing bias strips, that the warp or woof threads in all the strips run the same way, or the joining will show. When properly adjusted the two will form a right angle. In uniting bias pieces, the edges at either end of the two strips, as they are laid face to face, must overlap the width of the seam, so that the top of the strip will be even after the seam is taken.
Take paper 5x2 1/2 inches. Fold the narrow side that it may exactly meet the long, press it over into a triangle and cut through the fold. In order to compare the relation of measurement on the selvage to that through the bias strips take the larger piece of paper, measure one inch on each side and rule a line across. Now measure it all into one-inch wide bias pieces by placing the measure at right angles with the bias cut. Put a dot at each inch at the top and the bottom of the paper to the end of the strip. Rule lines diagonally across through the dots.