Why sew 1/2" seam then trim to 1/4"?
#1
Why sew 1/2" seam then trim to 1/4"?
I am in the process of making a tote bag. The instructions in several places say to sew 1/2" seam then trim to 1/4". I fail to understand why that is necessary? I mean I realize in THIS particular instructions if I changed it now the pattern size would be off. But what I don't understand is why it is necessary to begin with? It seems like extra steps. Can anyone enlighten me?
#3
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Join Date: Dec 2010
Location: Michigan
Posts: 11,276
It's easier to sew a wider seam, half inch or 5/8" in heavier fabric. Often, the instructions will tell you to 'grade' the seam after sewing. Usually you cut one layer down to about a quarter inch and the other layer of fabric a bit wider. This reduces bulk and makes the seam lay flatter. Cutting the entire seam down is less usual, but again it's difficult to sew a narrow seam in heavier fabric or a bunch of layers. Here's a youtube video on grading seam allowances:
http://www.youtube.com/watch?v=_gseV1cF9o4
http://www.youtube.com/watch?v=_gseV1cF9o4
#5
Thank you PaperPrincess. This make perfect sense to me. I am using Peltex and sewing two of those layers together, so I am sure it will be easier. Do you think I should grade these seams versus trim all to 1/4"? The pattern I am using has been disappointing on several points so I don't see any reason to follow her instructions on this point either. Lol!
#7
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Join Date: Dec 2010
Location: Michigan
Posts: 11,276
Thank you PaperPrincess. This make perfect sense to me. I am using Peltex and sewing two of those layers together, so I am sure it will be easier. Do you think I should grade these seams versus trim all to 1/4"? The pattern I am using has been disappointing on several points so I don't see any reason to follow her instructions on this point either. Lol!
#8
Wouldn't the size of your item be off if you only sewed 1/4 inch to start? Maybe that particular part is supposed to be a bit smaller so the designer has you sew a 1/2 inch to pull it in then trim your seam to remove the excess bulk. Or not.
#9
Senior Member
Join Date: Apr 2010
Posts: 696
I would think it allows you to top stitch a 1/4" without any problem. Sometimes it depends on the type of fabric you are using. A lot of purses and bags are top stitched to accent them, or if using a contrasting thread, maybe silk, it would be beautiful. Of course, your pattern says to trim down, but if your fabric unravels easily, I would suggest overcasting it or serging it. Good luck with it.
#10
Senior Member
Join Date: Feb 2014
Posts: 453
Could be the fabric that the pattern calls for. Also could be in a stress spot that is tight (or going to be tight), so they want to be sure the seam is secure. I find that the first time I make something, I try to follow the directions the way they have been written. After I have finished, I can start making any changes I want. I have patterns that I have changed seam allowances up or down, for my personal sewing comfort. JMHO
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07-02-2011 09:59 AM