Does anyone on here know what shrinkage rate to figure when using acrylic yarn for weft?  I am working on placemats for a friend - who wanted to match some placemats her mother had woven years ago.  Her mother used crochet thread for the warp and acrylic yarn for the weft.  The original placemats are approx 13" in width and 17" in the length.  When I did a computation on on-loom tension vs off-loom tension, I came up with weaving the placemats 15" wide an 20" in length.  Now that I have removed 5 of them off the loom, they are 14" wide - which is fine - but still 20" in length????  What in the world is going on??  Help, please.  Thank you.

Comments

Sun, 02/24/2013 - 14:15

endorph

no expert in this but I would think there would be little to no shrinkage in the cotton warp it just doesn't stretch much. And the Acrylic shouldn't shrink in width - except for draw in - Have you washed them yet? The cotton should shrink in the wash. . .
Sun, 02/24/2013 - 23:25

sally orgren

You measured take up (or draw-in, the difference under tension and then off the loom.) You didn't mention if you washed the material yet. The difference between the pre-wet finished dimensions and the washed dimensions = shrinkage.

I have woven projects of 100% Lily Crochet cotton, and had a 10% take up and shrinkage rate. I would not expect the acrylic to change much after take up, but as Enorph pointed out, I think the cotton might shrink once wet-finished. The yarn I used had a bit of a "hard" finish, in contrast to the unmercerized cotton I am currently weaving with, which in combination with the structure choice, has a 20-25% take up and shrinkage rate!

Another aspect of your yarn that makes a difference is how it has been spun. If the acrylic was knitting yarn and spun more lofty and stretchy, you will get a higher amount of take up (draw in) when off loom. 

You didn't mention your structure choice, but if mostly the weft is showing, another guess is that the warp would not have much take up, because it was not as deflected by the weft yarns very much.

If you haven't washed the placements, my guess is you will lose some length, but not so much width in your wet finishing.