Sunday 25 October 2009

Suit Jacket - pattern cutting

As you may have been reading over on my Five Costume Blog, I have been attending a College Course to learn some tailoring skills and improve my work quality.
My plan is to apply these skills to a variety of projects including an Inverness Cape over on my new Three Costume Blog.

I also intend to use the course to help kick-start my Tennant Suit work, which has rather lapsed of late.

The last work I did on the suit jacket was way back in May 2009, when I cracked the Faux Flap Pockets. (see right). That work is still valid, as too is the design I did for the Box-Pleat Breast Pocket I had done earlier (see below).

However, the one thing I was having issues with was the body shape of the jacket itself.

Being self-taught has got me a long way, but doing a fitted jacket was proving to be challenge that was stretching my skill too far. My plan is to gain the knowledge I need form the course to rectify this and crack making fitted jackets!

I discussed this with my tutor, Nicola, and she explained that I needed to first create a ‘block’ for my jacket.
A block is a term used for a non-pattern specific shape used for fitting, from which usable patterns can be easily derived.
She explanied to me the best way to arrive at my block.

Firstly, we need to draw everything in pencil at quarter-scale. From there we make up, again at quarter-scale, a thin cardboard three-dimensional test which checks it all meets up at the seams correctly. Once that is done, I can then work to full size to check sizing and fit. Finally, we can plot the position of the seams for a given jacket style to cut the pattern I need.

 The full size card version - or block - can then be used as a template onto which any future style of jacket can be projected.
(see above a range of variations of back shapes for jackets, all of which can originate from the same base pattern)

Well, that’s the general idea.

I have been measured according to the guide, taking some pretty standard ones such ad chest and waist, but also some more obliques such as a diagonally measurement from the middle of the back across the shoulder to the front under-arm point. These will be used to triangulate a better shape to the upper chest area.

The guide takes you through the stages of building the shape of the front and back by plotting a mix of the measurements I have taken and some fixed dimensions to allow for darts and tailoring.

This all sounds very easy, and the first few points are straight forward, establishing the spine of the jacket and the horizontal levels of the neck, under-arm, chest, waist and hem.

Then things start becoming a little more complicated. A number of the lengths are derived from calculations such as one-sixth breast, plus three-eights of an inch, depending on fit or sizing required. The worst is the over-shoulder measurement less 9 W of the back. I am at a loss to understand what it means.

As a result I am quickly mired in convoluted instructions.
Thank heavens I am only working quarter scale!!

I draw it up so far, and find things aren’t quite working with my own measurements (see right), so I start again, this time using the ones in the guide. At least I know these will work and give me practice at drawing the pattern up.
Results from this attempt are much more encouraging and I am able to complete the pattern.

At least I now understand the method to drawing it, and have finally understood the over-shoulder measurement less 9 W of the back, which had been foxing me for a while.

At the next class I am able to get myself measured properly by Nicola, my tutor. She produces much better measurements, and I am able to use these to start drawing the quarter-scale pattern to my own size (see left).

Now that I have drawn it up a couple of times, Nicola says it is time for me to jump on to the next stage and draw it full size (we are going to skip the small scale 3-D mock-up for now).

This time I am using a large gridded pattern paper to help me draw it nice and square (see below left).

With a little guidance and help from my tutor, I soon have it completed. She then show me how to retrace it over using pattern paper to separate the two pieces for pattern cutting (see above right).

She then explained that I need to add seam allowances to these pieces, as they are currently the net shape of the jacket, but college time was running short, so I took the pattern home to continue work on my own.

It feels like I am getting somewhere at last . . .

If you want to read the Cutter’s Guide for yourself and follow my progress, you can download it here:


  1. Oh Cool! I am getting there!!!!
    Let me know if you are interested in the results. I can provide images as well Before/after alterations.

  2. Hello, I just visit your web and finding the download link you gave. Unfortunately the link doesn't exist any longer. Could you give me any new link or will you send me the download version of The Cutter’s Practical Guide to the Cutting and Making of all Kinds of Lounge Jackets book? As I can find a place to buy one even though I have searched any where. Thanks in advance.

  3. This is a great website and great of donation knowledge about dressmaking too, i appreciate the quick replies of the administrator of this site at my request for more information and help.