Today I have some diagrams for you to help you make pattern pieces that can be used for making these divided bags.
Here are the diagrams for all three sizes:
Some of you will notice these don't include metric equivalents, and my apologies, but metric numbers make about as much sense to me as inches do to you! I give approximate metric equivalents in most instances, but when they need to be added up with the seam allowances included and get to another number with accuracy (the height of the pieces), it's just beyond me. But the basic idea of how to figure them out can be found in this post.
To make a long lasting pattern pieces, get some chipboard and use packing tape to join enough pieces together to accommodate the perimeter dimensions given in the pattern instructions.
Then mark the measurements given in the diagram above along both sides of the pattern piece.
The top number in the diagrams is for the upper section of the divided bag and the lower number is for the bottom section. They are oriented vertically, so you'd mark your piece out tracing from the number down the side, across the bottom, and up the other side.
The fastest way I've found do to this, in the least amount of space, is this:
For the bottom section of the bag, begin by making a registration mark off to the side of the lower number. In the next step, the horizontal line across the top of the section will be hidden, so you need these marks to orient the piece.
Then trace from the lower number down the side, across the bottom, and then up to the lower number.
Turn the pattern piece upside down, line up the edge with the registration marks, and mark the top of this section. Instead of turning the piece upside down, you can simply keep sliding it upward. The only issue with this is the pattern piece needs more space to maneuver.
Slide the pattern piece down until the lower number matches the registration marks, and trace up the side, across the top, and then down to the lower number.
Now you have two pieces outlined for the bottom section. Repeat these steps for the top section using the larger numbers marked along the sides of the pattern piece. Then sew the sections together using a 3/8" SA.