Shorten the stitches even more... if you are using 15 stitches per inch (measure an inch) then go to 18-20 per inch... your stitches shouldnt be breaking, even with copy paper. The *folding* at the seamline helps too. I have used 20 and 22 pound copy pair for hundreds and hundreds of seams and never had the stitches break. How old is your thread? And as someone above said, printer ink will run on light fabric; I wouldnt moisten it.