~tricks of the trade: turn of cloth allowance~

I was prompted by a couple of questions in the comments on yesterdays post about my pink jacket to write this post. First I started with a brief reply in the comments, but ended up with a complete essay instead!  Cloth allowance (or turn of cloth) is a simple but really important concept to understand if you want a professional finish to your sewing.

So what is ‘cloth allowance’?
It is an allowance to compensate for the extra millimetres taken up when fabric is folded.  See this pink fabric – when folded it uses about 4mm of fabric just to turn the corner:

This fabric is quite thick, most fabrics will use about 2mm, and chiffon will use hardly anything.  The thicker the fabric, the more cloth allowance you need.

Why do you have cloth allowance in a garment?
On most bagged out edges we don’t want the seam to be visible, we want it to sit slightly underneath the edge out of view.  It just looks better!

For instance – the edge of this pocket flap, so the lining is concealed:

The edges of these neckline and armhole facings:

The edges of this collar:

How do you add cloth allowance?
To enable the seam to lie underneath the edge, we need to add an additional allowance to the edges of the outside piece (or alternatively trim some off the edges of the inside piece).

For example:
The pocket flap – make a separate pocket flap lining, but trim 2mm from all bag out edges (red line):

For the neck/armhole facing, trace the outer bodice and trim 3mm from the neckline and armhole edges (red line):

Collars (and lapels) are a little different, because they have two folds – the roll line, and the bagged out edge:

To accommodate the bagged out edges, I added about 5mm to the outer edge of the top collar.

To accommodate the fold over the roll line I added an additional 6mm.  This was done by adding 3mm at the neck edge for the stand, and 3mm to the outer edge for the fall.

So a total of 11mm extra length was added at the centre back for my pink fabric. This is quite a lot, most fabrics only need about half this amount.

The front facing on a typical jacket deserves a special mention too.  The front facing is outermost at the lapel, and becomes innermost below the break point.  You need to add cloth allowance to the front facing around the lapel, taper it to zero at the break point, and subtract it from the front facing at the front edge, like this:

You can compensate for cloth allowance whilst sewing, by purposely misaligning raw edges or pinning tucks, but I’m not a fan of that method. As a patternmaker I prefer to do this at the pattern stage because it is more precise, and maintains consistency for bulk production.

Note that in some cases you will not require cloth allowance – if for instance you are going to pipe or bind an edge, you will want both raw edges to meet exactly.

Your pattern may or may not have cloth allowance incorporated – to find out lay the pieces on top of each other and see if there is any difference, or enough difference for your type of fabric – and adjust accordingly.

How do I know how much to add on/take off?
The amounts noted above are what I actually used in those examples, so you can use that as a guide.  You will need to add more or less depending on the thickness of your cloth, and you soon get a feel for what you need with experience.

You can also gauge approximately how much you need by using a dress stand, or a friend.  Cut two pieces of equal width, pin them together at the neckline, and fold your mock collar down – your ‘top collar’ will fall short like this:

This excess is intentional, and trust me it will sew together alright, just make sure the centre notches match!  If you do have difficulty (I sometimes have problems getting small slippery pieces like pocket flap linings to fit) sew with the longer edge underneath, so the feed dogs of your machine assist you to ease the longer layer in.  Once you turn and press, everything will fall into place just like magic!

Now you can make your cloth go around the bend, instead of it making you go around the bend! Here’s to happier sewing!