|After I’ve washed a sample piece of my woven fabric, I know just how much I can expect my actual piece to shrink. Then, I mark my adding machine tape accordingly. For example, if I discovered the cloth shrank 5% warp wise, I’d add 5% to each weft band’s measurement. (To figure percent of shrinkage, see below.) This way I’ll know the bands will turn out to be the size I want after the cloth is washed. Say, if I wanted bands of 3 inches and 5 inches, then I’d go to my calculator and do the following: 3 multiplied times .05 (or 5%) equals 0.15. Then I check to see what fraction is closest to 0.15. I see that 0.15 is a little more than 1/8″ (0.125). (How to find the equivalents of fractions and decimals is explained below.) Then I’d add that to the 3″ (3 1/8″) and that would be the length I’d mark on the tape and how tall the band would need to be woven to have it 3″ after washing. The 5″ band would need to be woven 5 X .05 = .25 then 5 + .25 = 5 1/4″. BR>
Percent of shrinkage
To calculate the percent a cloth shrinks accurately, before washing, note these measurements: the width the warp was in the reed and the length of the cloth measured on the loom. Then measure when the cloth is dry after washing (finishing). Subtract the smaller (the after washing) number from the larger (before) number to find out how much the cloth shrank. Let’s say a 10″ long cloth measures 8 1/2″ after washing. The difference is 1 1/2″-the amount the cloth shrank. We want to know what percent 1 1/2 is of 10″. As my 5th grade teacher told us to do to figure out percent, “Divide the little number by the big number.” That would be 1 1/2″ divided by 10″ which equals 1.5 divided by 10 = .15 which is 15%. These percentages tell how wide you need to make the full-sized warp and how long you need to weave it, measuring the cloth on the loom.
|The above information can be found in Peggy’s Book 3: “Weaving and Drafting Your Own Cloth.”|