Comments on: The rules on seam allowances pt.2

By: Kelley Charpentier

Kelley Charpentier — Mon, 11 Oct 2010 16:29:01 +0000

Are there any hard & fast rules to serging seam allowances? I work with some silk (and other thin fabrics) & if I serge the edges and then press it, you can see the serging. I’ve been pinking some edges, but was wondering about other options. Any help is appreciated. Thanks!

By: Million

Million — Fri, 05 Feb 2010 23:26:43 +0000

Kathleen, you must have just lost it when you saw the seam allowances I used for my older projects (since I hadn’t perfected the patterns I added extra material to the SA in order to compensate). Thanks for clarifying.

By: LisaB

LisaB — Fri, 05 Feb 2010 17:41:43 +0000

I’ve got a Juki MO-2512. In metric it looks to be exactly 5 mm and 8 mm. Interesting! Juki overlocks must be configured in metric, which would make sense.

Betsy, I know I fiddled with tensions, but it’s too long ago to remember which ones and which direction. Sigh. Maybe we’ll give this another try following your advice.

By: Dawn

Dawn — Fri, 05 Feb 2010 14:41:05 +0000

Ohhhh! She exclaims! No rigor mortis here. You just clarified everything for me! I provided a pattern that specified 1/4″ seams, and in trying to adhere to that they are sewing too close to the edge, maybe because they’re not used to it. It’s hard when the factory is trying to do “whatever you want” and you don’t really know what you’re doing! I did not understand to draft the pattern to 3/8″ (which the factory said is their standard allowance) – I did 1/4″ because the seams are being sewn using a 4-thread overlock. Need to add 1/8″ to the patterns asap. Thank you!!

By: Elizabeth

Elizabeth — Fri, 05 Feb 2010 14:09:05 +0000

Both my industrial sergers/ overlocks do the same 3/16″ and 7/16″. I have a Juki MO3316 5 thread serger and a Merrow 3 thread overlock. Both have been adjusted and serviced, the threads are not pulling, even if you remove the thread and let the needle mark the fabric/ or paper, the markings show the same measurements.
My question is when I do patterns for clients, do I make them according to the seam allowence on my equipment since I am the one sewing the samples or with the 3/8″ and 1/2″ standard seam allowences in case they have a sewing contractor who has standard machines, especially if the client doesn’t have a contractor yet to ask?

By: Kathleen

Kathleen — Fri, 05 Feb 2010 13:47:54 +0000

Lisa -good point, I should have mentioned this. I don’t remember what model you have but some overlocks (and single needles) are not configured to imperial measures but metric. Can you try that again and measure in centimeters? I imagine it will come out in even measures. The only modification you’ll need to make is to add your seam allowances in metric rather than imperial measures. And maybe Betsy’s suggestions will work too, I wouldn’t know not having had that experience.

By: Betsy Johnson

Betsy Johnson — Fri, 05 Feb 2010 13:35:01 +0000

“DH and I adjusted the knives to the right a while ago trying to get the more standard 1/4″ & 3/8″, but I couldn’t get the stitches to form correctly. Evidently, something else needed to be adjusted, too”

Did you loosen the tension on the looper threads? With the additional distance between the needles and the edge, each stitch needs more thread length.

By: Lisa Brazus

Lisa Brazus — Fri, 05 Feb 2010 03:51:26 +0000

Kathleen,
Anything written on seam allowances and different types of seams is beneficial. My students look at me like I am an alien when I tell them that the seam allowance depends upon the machine being used, the type of seam being sewn, and the type of fabric being used. They want a more definitive answer.
If you ever write that pattern book I will purchase it yesterday!!!
Btw I was lol about your reference to rigor mortis.

By: LisaB

LisaB — Fri, 05 Feb 2010 02:34:40 +0000

Kathleen, thank you for clarifying.

My industrial overlock is a 3-4 mock safety stitch. I just double-checked to make sure I wasn’t crazy… The left needle finishes at 5/16″, and the right needle finishes at 7/16″. For the last year since getting the machine, I’ve been adding 1/8″ more than that as seam allowance on my knit patterns. It’s frustrating to mark off 7/16″ or 9/16″. Anyway, DH and I adjusted the knives to the right a while ago trying to get the more standard 1/4″ & 3/8″, but I couldn’t get the stitches to form correctly. Evidently, something else needed to be adjusted, too, but I didn’t know what. I ended up moving the knives back to their original position and just deal with the odd seam width. Maybe I AM crazy…

By: Kathleen

Kathleen — Fri, 05 Feb 2010 00:44:27 +0000

SSb-2? I thought it was SSa-2 but should have been the EFa-2. Btw, let me know how that worked out for you later.

Btw, there’s a third seam class standard beyond the 751a and ISO designations -colloquial. We’d call the EFa-2, a simple or single turn double stitched. Welcome to my world.