Use these unique interlocking circles to add or subtract seam and hem allowances to your sewing patterns.  Available in cm or inches.  Each kit contains circles to add from 0.5cm to 3cm or 1/4" to 1" and there are two options of centre hole for each: small for a pencil, large for a fabric pen.
 
They're very easy to use, just keep the edge of the circle on the pattern line.  It doesn't matter how you keep it on the line - roll along a ruler, push it with your other hand, guide it with your finger - whatever works is the right way!   The trick is to focus on the edge of the circle and not on your pencil.  If you need more than the biggest circle, draw one line then use that as your guide to add another. 
 
Great for
patterns which don't have seam allowances (Fibermood, Burda Magazine etc)
drafting facings
Removing seam allowances for hacking
Adding seams to self-drafted patterns
Marking your sewing or top-stitching line, for precision sewing
Drafting echo quilting lines
Marking pad stitching lines 
Drawing rounded corners
And more
 
Thank you to everyone who tells me how they use them, you're all an inspiration!
 
 
I've sent these all over the world and have been bowled over by the response.   There are lots of reviews on Etsy, including: 
"I've been an intermittently avid seamstress for nearly 50 years, but have never seen this. It is a great tool to add to my kit. So glad to have it." and "I love this shops sewing notions. These seam circles are simply GENIUS. GET SOME!!".   Thank you so much, comments like these mean a huge amount to a small indie business.
 
Made in Scotland from FSC approved cherry wood veneer. Each tin is hand-stamped with permanent ink because it adds individuality but more importantly, it avoids over-production.
 
If you're buying from outside the UK - please buy through Etsy to have the correct tax applied. This should save you paying any additional  local handling charge.