I don't think you understand what I was trying to describe. The "compressing" you're talking about is from side to side or top to bottom, and only when sewing pleats or channels into 1/2" sew foam. The insert piece I was doing shrank 3/16 of an inch from 11 and 3/16" to 11" side to side after having the pleats sewed into it. I knew that ahead of time, because I did a test with a small piece of the fabric and foam I was using.
The answer is no, it varies with different fabrics and different sew foams, and I would call it shrinking rather than compressing. That's why I recommended doing a test run with the fabric and foam you'll be using to see how much it shrinks before you lay out the lines and sew your finished pleats. Vinyl may shrink less than cloth, leather and Ultraleather depending on how stiff the vinyl is.
No one lives forever, the trick is creating something that will.
Last edited by DanTwoLakes; 08-19-2010 at 11:11 PM.