Essential Tutorial: Straighten Fabric Edge

May 9, 2017

straighten fabric edge

This is an essential skill when making anything that requires straight edges like quilting, tote bag straps etc. Invest in a good rotary cutter and a decent sized self-healing cutting mat. Bigger is better, I use a 18″ x 24″ mat because that is what I bought a long time ago, I would go bigger if ever I get the chance. Go slowly with a rotary cutter, you will be sorry if you don’t. Also, make sure you *STAY ON* the cutting mat with the cutter, I have accidentally cut through table cloths and even made a nice straight cut onto my antique table top (cringe). This was before having a table dedicated to crafting.

Caution* this is a very image dense post and there are lots of descriptive words ahead. For those who have never touched a rotary cutter and cutting mat in their lives, this post is for you. For those of you who have done this before, just follow along and try not to distract the rest of us 🙂 These are also written from the perspective of a righty. I’ve added directions to make it lefty friendly where necessary.

Step 1: Fabric Prep


Fabric usually does not come home from the store all straight and aligned. We need to do that ourselves if we want to create nice and straight cuts. A little fabric knowledge to drop on you first so you can follow along: The straight sides of the fabric, perpendicular to the store cut edge is called the selvedge. It is usually considered to be a straight edge (but not always! just look to see) and can have either little fuzzies, holes, a more tightly woven edge, printing to tell you the manufacturers/designers name or a combination. The selvedge is usually cut off before the project pieces are cut out, but in some cases, if you need a half inch more fabric that will eventually go into a seam, it can be used in an emergency. Be cautious about selvedges that are a little more tightly woven, they are the ones that can cause trouble.

Get on with it already:

Fold fabric in half with selvedges on the same side.


To get a straight edge from which the strap will be cut, fold the fabric again so that the two selvedge sides are lined up with the first fold.  Here is where experience comes into play. When lining up the selvedges and all these edges, the fabric might not want to lay flat. The goal here is to make the fabric smooth and comfortable, ignore the uneven cut from the store for now. Line up the selvedge edges and the store cut end to try to make a 90 degree corner, you may find the fabric doesn’t want to fold nicely down the middle. In this case you need to make an adjustment. Slowly move the store cut ends until the middle fold lays flat and there are no large wrinkles in the fabric and the selvedge edges are still lined up together. Now that you have the middle flat and happy, take the selvedge edges and fold them up to meet the middle fold. Which looks like this, below:


We are going to use the straight edge of a long ruler to cut the uneven end off with a rotary cutter. If you have never used a rotary cutter, treat it with care, they are sharp! Using the clear ruler, line up the straight edge (as shown below) past the shortest spot on the store cut.


Once you know where the straight edge needs to be, we need to make sure the straight edge is perpendicular to the bottom fold (the original ‘middle’ fold and selvedges edges are at the top). Fabric should be folded into fourths lengthwise and we are using the bottom folded edge to check that the ruler is forming a 90 degree angle with the straight edge you are going to use. Make sense?


Proceed with Caution, Sharp Objects ahead:

Use the rotary cutter to trim off the uneven ends.

Note to lefties! The images show what righties need to do, if you are lefty do the same steps but before cutting, turn your cutting mat 180 degrees so that the uneven edges are to the left of the ruler. Make sure nothing slipped during the turn.

Hold the ruler with your non dominant hand with at least one finger or your elbow on the cutting mat so the ruler doesn’t shift at all. Taking the rotary cutter in your dominant hand, undo the blade cover and place the side of the cutter up against the side of the ruler. Starting closer to your body and using a slow and steady motion, cut the fabric in one long stroke away from you. Do it in one long motion and make sure you can feel the mat below you. A sharp cutter should be able to do this in one pass, if it doesn’t, replace the blade when you can.


Unfold, smooth and lay out your fabric flat and look at the straight edge using the ruler and selvedge edges to check. They should be perpendicular. Look at the entire length, does it look straight to you? Do the same process again if necessary to straighten your cut, just don’t take off too much fabric when cutting, we want to save as much as possible. All done! Now you can move on with your project knowing you have a nice straight edge to start and now tote bag straps are within your sewing skill reach, check out how here.

Questions? Comments?



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