The Upholstery Forum

I'm making my first pattern for a truck bench seat. I created a pattern from the old cover (which has 1/2" and 1/4" scrim foam on the plate and boxing, respectively), and for practice I created a custom pattern. The old cover pattern is substantially bigger than the custom pattern. It seems the old pieces were originally cut bigger to accommodate the foam. I'm not sure which pattern to use. Are covers made with custom patterns always tighter than the original? Thanks!

When you make a pattern, you control if it's larger or smaller. Are you cutting the edge of the material at the seam and then putting in your seam allowance from that edge? That would easily make your cover 3/4" - 1" smaller.

The old (fabric) cover has 3/8" seam allowances. I didn't cut them off because I can only see the needle holes consistently from the foam side, and I thought that would be inaccurate. I traced the outer edge, then marked a line 3/8" inside that. I then added 1/2" seam allowance to that. I scrimmed and sewed one plate, and it fits like the old cover when I position it on the lines I drew on the molded foam. I was happy with that until I made a custom pattern for practice that turned out smaller. I've watched many videos where trimmers use old covers with sew foam for patterning, and they never shrink the pattern pieces to make them fit like a custom pattern. John explains why we use sew foam in his seats course, and he makes a pattern from an old cover with no sew foam (except on the inserts). I guess I'll proceed, and if it's not tight enough I'll start over with a custom pattern.

It may vary with different upholsters. I make my patterns off the sew line, then add my seem allowance to that. I have on occasion fudged in 1/8" on the sew line just to tighten the cover a bit.

My cover made from the old-cover pattern turned out snug but not tight. I was able to install it easily. But I think a custom pattern would be too tight. I think I'll try your 1/8" idea. As a beginner there seems to be a lot of guesswork here, which only experience can reduce. Thanks for the help.

Hit and miss here especially if you are laying the cover down over the old foam. I would stick with the original pattern.