Seam Allowance Boxes

Dear Users

Is anybody aware of a possibility of making seam allowances boxes or any workaround.

to include correct seam lengths in patterns, the sewing order needs to be respected in the seam allowance; either with a notch or a box; which needs to be put in a right angle of the seam to be sewn first…


Hi again, @jan :slight_smile:

I’m not too sure if I understand what you want. However… Your pattern can be exported as a vector file and imported into a graphics program like Inkscape or Adobe Illustrator. Then you could edit the seam allowances as you please :slight_smile:

That being said, you can play around with these. I’m not too sure what I’d use them for, so I haven’t gotten much joy from them, but they are worth exploring, if I look at your markings:


Please let me know what you think :slight_smile:

Dear Grace

thank you, you´re a real asset to the project… i used illustrator only to show what i needed:)

i also tried the seam allowance details a little bit and found out that the two options “first and second edge right angle” get me the closest to where my patterns need to be… but they are somehow different from what I have learned is correct…

i have attached another illustration of a back-sidepiece-yoke situation to better explain my issue…

the pieces are sewn in the following order:

  1. the yoke and lower back; the distances b24 and b23 need to be the same (very important: on the sewing line and on the line of the seam allowances)

  2. side piece is attached to back, there is a little ease in the pattern which needs to be evenly distributed between waist and armhole therefore i put the notches in the middle (C18/B35). to achieve a flawless result the edges of the seam allowance needed to look something like this… (note; in this situation the angles of the sleeve line cause something like a 4mm difference)

  3. the sleeve is set in… as a last sewing step this seam allowance automatically adds up:)

I have actually figured out a workaround; by putting a nodge right before the ending point of each sewing distance, i also have equal sewing distances… downside; its quite a lot of additional work…

thank you for your inputs

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Dear @jan

Thank you for the compliment :slight_smile: I’m just a home sewer who found Seamly2D a few years ago and then had to learn how to create sewing patterns, so no formal training at all :slight_smile: My way of ‘giving back’ to the project was to learn how to use the program and to answer questions and give assistance on here (the forum). I often wish that I had studied programming - so that I could help more with the program side - instead of accounting, but unfortunately, it didn’t happen that way :slight_smile:

There is another work around that you could try… That is to add a node at 0.5mm from your node B23 in your pattern detail, then set the B23 to have 0 seam allowance after with By first edge right angle and the new node to have 0 before with By second edge right angle.



It means that the line will be extended by 0.5mm but perhaps you can find a work-around for that :slight_smile:

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