Wednesday, September 14, 2011

drafting the trouser back

Here we are, ready to start drafting the back of the trousers.
I have cut out the front pattern, laid it on a new piece of paper, and traced around it.
I have then drawn in the horizontal and vertical construction lines, and the points from the fronts that are needed to draft the backs.


Pivoting from 14, sweep from 9 to 16, 2 1/2 inches.

17 from 14 and 18 from 12 are each 1 inch (for seams).
The back of the trouser leg is made wider than the front. The fronts were measured at 1/4 total knee and hem but they have 1/4 inch seam allowance included in that. The backs are made an inch bigger, but they also have seam allowance included. Am I making any sense or just making something simple confusing??

Lets move on.

19 is 1/2 of 0 to 9
20 from 0 equals 1/3 scale plus 1 inch.
This is to establish the CB seat angle, so go ahead and draw a line from 19 to 20 and extend it above the top line by a few inches in preparation.

The next instructions help to find the width of the hip. Measure from 6 to 3 on the fronts, take that number, and starting at 20, measure over to the hip line 1/2 seat plus 2 inches for seam allowance and ease.
22 is 2 1/2 inches up from the top line. I am thinking it is along the straight line from 19-20.
Hollow 3/8 inch at 23. The centre back line has shaping.
Now to measure the waist you are going to start by measuring the front waist, and apply that number at 23, measure over half the total waist measurement plus 2 inches to find 24. Measure over 1/4 inch and square up to 25. The width of the waistband here is 2 inches the same as it is on the front.
The next instructions have a "typo".
It should read 26 from 22 equals 1 1/2 inches, shape up 1 1/2 inches to 27 and complete top.

Measure over 3 1/2 inches from 25 to find 28 which is the dart.
The dart should be squared to the waistline in this draft.

Now the dart can make people confused. The dart has seam allowances. The width of the dart is given as 1/2 inch but it has 1/4 inch seam allowances so it adds up to 1 inch in total.
The dart length is given as 4 1/2 inches and cut out, but it is much longer when sewn with the seam allowances. I have drawn the allowances in so you can see it.

Now you have all the points needed so you can draw in your seam lines.
The inseam is pretty straight from hem to knee, then hollows out to come to point 16.
the outseam is again pretty straight from hem to knee, then ever so slightly hollows inwards from knee to hip and curves outwards over the hip through point 21 up to point 24.

When you shape the top line, make sure the dart legs (there's another terminology word) are the same length. If you just draw it as I have done for an example, one side ends up being slightly longer and you don't want that.
Dart Legs: the seam lines of a dart.

Draw in the seat seam as shown. I like to put the inseams together: point 9 of the fronts to point 16 of the backs and draw a nice line from one to the other. Follow up to 20 which will be a bit of a bump in the line as you hollow out to get to 23 and flare back out to 22.

Curve the hem downwards 1/2" as shown.
Cut out your pattern.

The photos were taken on different days - one sunny and one overcast so I apologize for the strange colours going on.

Next I'll just show you how to make a pattern for the fly and the waistband interfacing.

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