Sewing with leather pt.2

Today’s entry will illustrate an example of how to lay out a pattern using what you learned in yesterday’s entry. I hope the take away for everyone is how invaluable sketches can be as frequently used visual tools. Here is a sketch of the pattern we’ll be working with, style #22304. The sketch shown here is not technically correct, I did this for resale for the home sewing market eons ago so it was shown with and without the hairpipe option. In real life, you’d show it with or without the hairpipe but not both. Although identical (except for hairpipe), they’d have different style numbers.

For simplicity, I’ve followed Barb’s advice (thank you!) and labeled the pattern pieces on the sketch. In real life, we wouldn’t do that, not usually although it could be a good idea for leather construction. In real life, pieces aren’t labeled A, B, C etc. They have PN numbers instead. Again, the letters are for the purposes of this tutorial only, and should not be confused as a standard practice to adopt. In summary, the first step in laying out a pattern is making sure you have all the pieces you need. You don’t want to know how often this mistake is made. At this point we’ll compare the sketch to the cutter’s must:

A-Right center front
B-Left center front
C-Right lower front
D-Left lower front
E-Upper side front (2)
F-Lower side front (2)
G-Center back (2)
H-Lower (center) back (2)
I-Upper side back (2)
J-Lower side back (2)
K-Under collar (2)
L-Top collar
Not shown:
M-Upper front facing (2)
N-Lower front facing (2)
Linings, fusibles etc

By now you should have noticed that some of the pieces you might think are two per (center fronts, lower center fronts) are not. If these were two per, the “V” at the overlap wouldn’t match. An explanation of that little problem is here.

As much as you want to get to the fun part, it is critical you’re certain the pattern pieces are labeled correctly before you start laying out pieces. Each piece must have an information block among other things (pt.2). For our purposes at this point, we’re concerned about nap. Your nap arrows must be correct. Surely I’ve written an entry on the meaning of grainline arrows but I can’t find one. Below is a sample of nap arrow.

The reason for this is based on nap of the hide I explained yesterday, your pieces can only be laid nap down. If you lay one front nap up and the other nap down, it’ll be very obvious once the item has been constructed because the sides won’t match; they’ll be what we call “shaded”. You may well be the rare exception who will be able to keep track of nap but usually when you get into the jig saw phase of laying out pieces, you’ll only be looking at area and shapes, not text instructions written on pattern pieces. It’s a spatial thing, not verbal. Plus, so many pieces look similar top to bottom or even side to side, it gets a bit confusing. Here’s a sample of one piece from this pattern, can you look at the technical sketch and know the direction these should be laid in?

The piece in sketch 1 is the same piece in sketch 2. The right and left sides of the piece are similar in angle and length. Without a nap arrow, it’s truly difficult to know how to lay it on the hide. With a nap arrow, less reading is required.

Well, I’d planned to finish more than this today, intending to actually show how to lay out the pieces on the hide (my least favorite thing to do) but I think it’d be a bit much so I’ll leave that for part three. With all the artwork, it took me longer than I expected to write this one and artwork is my weakness for sure. For the next entry I have to re-size all those pattern pieces from my CAD program and flip and mirror them every which way to lay them on the ugly hide I drew yesterday. Ick.

Related entries:
Poka Yoke pattern making (leather pattern design tips)
Piece naming conventions (tips to prevent confusion)
PN Numbers
Checking a pattern pt.1
Checking a pattern pt.2

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