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 shrinkageTo 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.
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| The above information can be found in Peggy’s Book 3: “Weaving and Drafting Your Own Cloth.” |
Peggy,
Thank you for posting this valuable information to your blog. I am attempting to weave very simple lengths of cloth out of cotton weft and warp. I wove all of the initial pieces to the size I needed and then tried to determine the shrinkage from each of them to adjust for length the next time I attempted the project. I was bewildered because when I made the adjustment using the inch measurement and adding the length the piece shrunk to the next project, I still came up short. I also found that the longer the strip, the more I lost to shrinkage. Haven’t done a percentage as you suggested, but does the way the piece is woven have anything to do with shrinkage? If woven tighter on time and looser another? My strips are 6 inches wide and different lengths long. Then there is the idea of re-weaving the weft yarn again which I believe will be another puzzle as the weft will shrink but the weft probably won’t. Any ideas or suggestions?
Thank you in advance for your response,
June
Several thoughts come to mind. Is your loom wide? If so your little 6″ wide strips can be beaten too much or it’s too hard to control the beat. Perhaps you can use a short reed to reduce the weight of the beater. More ends per inch can help reduce beating too much (see my info on sett). A looser fabric will shrink more because there is room to move and shrink, so a denser fabric might work. I think you are saying that the pieces may differ–I think you need to control the beat and that you should do with the sett. Even if you don’t want a dense fabric, using more epi than ppi will put more friction on the reed and allow you to beat naturally, without trying to beat very light with every pick. All your samples need to be the same width if you want to get good shrinkage info. so read my info on sett ASAP. My book #1 Winding a Warp and Using a Paddle has a whole chapter on sett. “Weaving for Beginners” has a good amount but for reference and the theory, see Book #1. Let me know if this helps and if I understood your questions. Peggy