Wednesday 30 September 2015

Sewing an accurate scant quarter-inch seam allowance

It’s hard to believe (well for me anyway) that the world wide web, that we take so much for granted these days, wasn’t around when I first fell in love with quilting. When I first started in my teens, I taught myself the basics from books and magazines, using templates cut from cereal packets, and cutting everything with scissors!! It wasn’t until I came back to this wonderful craft in my twenties that I discovered the huge wealth of information, generously given for free, on the hundreds of quilting websites and blogs that now exist. I have learnt so much from these wonderful quilters, and continue to do so.

Many of these talented people write blogs where they share their latest creations as well as the latest tips and tricks to help us all in our projects. You can see some of them in the right-hand column in My Blog List. It is these people I would like to share with you in this series of how-to blogs. I already include links in the “I’m stuck, help!!” section on sewmotion, but I thought I would highlight some of the essentials to help those new to quilting.

This week we’re starting with the scant ¼” seam allowance. Now, I have to admit, I have learnt something new today… I like learning new things, but this was a bit of a surprise… my ¼” stitch on my machine is actually not a ¼”!! I know, shocking! Well in fact, it is a ¼”, but not a scant ¼”. You will come across the term scant in most quilt patterns, and it means that you need to sew about a thread’s width shy of ¼” to give room for the thread and the fold in the seam. 

So, for the purposes of this blog, I followed a couple of online tutorials to check my own seams. The first is from the lovely Amy Ellis at Amy’s Creative Side. She uses a ¼” foot on her machine, whereas I use my standard foot with the needle moved to the right (the ¼” stitch setting on my Janome). 

If your machine doesn't have this setting, most machines allow you to move the needle to the required position. To set this up for a ¼” seam, place a quilter's ruler on top of the lowered feed dogs so the ruler lies nice and flat (above left). Align the right edge of the ruler with the right edge of your presser foot. Slowly lower your needle so that it's not quite touching the ruler, then move the needle until it lines up with the first ¼” line on the ruler. Now you can use the edge of your normal presser foot as a guide to run the edge of your fabric against. If you would like a clearer mark, you can stick a thick piece of tape onto to your machine to give you more of a run up - The Fat Quarter Shop has a great video showing more about this guide here.

So back to checking for scantness...

Following Amy’s tutorial I cut a few 2½” fabric strips, then used the first two to sew a ¼” seam as normal. However, when I came to check my block size, I was out! This explains so much! It may seem to you that this tiny amount wouldn’t matter, hey, its only a smidgen out right? Wrong! If you imagine this amount out on say 20 blocks… that smidgen soon adds up to more than an inch and will cause problems if you're following a pattern.

Now, I probably haven’t noticed this before as I’ve used the same stitch consistently throughout my sewing, so I wouldn’t have been out when matching seams and rows to each other. However, when I’ve come to measure the whole quilt I do sometimes come up short. As I am normally following my own pattern, I've just gone with it, but if this is your first quilt, or if you're enjoying some complicated piecing, you'll want to get it right.

So, following Amy again, I went back to the machine and moved my needle .8mm to the right, setting it from 8.3 to 9, and tried again.

And what do you know, it worked perfectly! I’ll just have to now remember change this setting every time I sew.

If you don’t have a ¼” foot or stitch on your machine, this tutorial from Connecting Threads explains how to place tape down on the front of your machine to use as a guide for your fabric. Once you have tried this method, I suggest you then do as Amy did and press your seams open to measure your block, just to make sure your seam is a scant one.

Today I'm linking up with Tip & Tutorials Tuesday over at Late Night Quilter, and Sew Fresh Quilt's Let's Bee Social - come and join in the fun!


  1. It is amazing how that tiny difference can make all the difference! It usually doesn't matter on many of my projects, but sometimes it is so important! Thanks for the reminder...

  2. I had always sewn my 'own consistent 1/4" seam' and it worked because they were all the same but I had to really learn for the DGC blocks because as you say it makes a HUGE difference. I have a 1/4" foot but even that didn't work precisely enough so I too played with my needle position. It's pretty satisfying get it right isn't it?!!


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