Welt and paper jig

As I mentioned yesterday, you’ll need a pattern for a paper jig into which you’ll stick the welt and press it. This is to compensate for the machine folding. Here you’ll see the inner jig is 1″x9″. The length of it isn’t that important but it should be a bit longer than the welt which is 8″.
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The outer jig is 3″x 9″ and it has two folds. The center section should be 1″ plus a tad (I’ve used 1/16th here) because of something I call “bend allowance”. I’ll write about bend allowance at the close of this post so just trust me for now.

The pattern pieces for the welt and interfacing is shown here. You’ll notice these pieces are color-coded.
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The shell pattern piece is written in black ink. Black ink means shell or self. The red pattern piece is the interfacing, that’s what red means. In production, you need both pieces, hacking off the shell piece Will Not Work. The last patternmaker I knew who tried to fly that one by, had the air let out of her tires by someone more digruntled than she was. And she thought I was picky. The dimensions of the welt are 3″x 8″. The canvas piece is 2 3/4″x 7 3/4″; it’s smaller by 1/8″ on all sides. You’ll also notice that the black piece has a red outline too. Well, that’s the way you “tell” other people that an interfacing piece goes there so if they don’t have an interfacing piece they need to find one and while they’re at it, check for whatever other pieces they may be missing because when somebody does sloppy work, they’ll do all-around sloppy work and you can’t guess which part of the job they’ve decided to do or not do.

You’re also supposed to show where the pocket lies on the garment on the pattern. The one shown below shows the cross hairs of the welt and the interfacing needed to stabilize it. I realize that the pocket marking on the garment is green rather than black. A green pocket (or any green detail) means that the pocket is not cut of the same fabric as the shell; it’s a contrasting fabric. Green (or purple, these are interchangeable) means contrast fabric. While I have your attention, pattern pieces marked in blue are linings. That is all.
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For this exercise, you’ll need 1 shell welt and 2 interfacing pieces. One of the interfacing pieces is for the welt. The other one is for the shell, the front or whatever you’re applying the pocket to. So go ahead and cut and interface those pieces.
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Back to the paper jig. Cut it out (cutting all the lines away) and nest the smaller piece into the larger one and staple one end of it just like you see here. Fold one side of the jig over the welt, then the other, pressing creases into both sides as shown below.
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Now you need to mark the stopping and starting positions because I don’t think any of you have any laser sights on your machines. As tho I did. So, I mark these. You can draw a line all the way across but I’ve restricted my marking to just the left and just the right but not the center. You can do whatever you want as long as you mark off 1″ from either end.
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Here both ends are marked and this piece is ready.
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Now you have to mark the shell piece for the pocket placement. Normally I’d use white chalk or wax pencil but that doesn’t show up very well so I’ve used pencil instead. These dots or drills should be 1/8″ shy -on either end- of the finished welt pocket dimensions. Since our pocket finishes at 6″, these drills would be 5 3/4″ apart. My sample is marked at 6″ because that’s my preference at home but I wouldn’t make a pattern for a customer like that. You can do what you want but you have to mark it correctly if it’s for production which means marking it shy of the finished dimensions. Okay, that’s enough for today, do all this and we’ll sew tomorrow.
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Now, back to bend allowance. First off, you’re not going to find those words linked together in any pattern making books. It’s a term I use to describe the creep of materials when they’ve been joined in the same space. If you only work with dress weights, you don’t notice creep as much but I’ve worked a lot in leather and wool coats so creep can be a real problem and you should adjust for it on lighter fabrics anyway.

This situation of the paper jig is that the inner piece is exactly 1″. The outer jig cannot fold at that same point relative to everything else especially once you’ve stuck a wad of fabric in there. It needs some bend allowance. That’s why the center portion of the larger paper jig piece is wider than the center paper jig piece.

Once you stick your welt into your paper jig to press it, you’ll notice the fabric hangs out, extending past the lip of the larger paper piece and that’s okay, that’s creep. If you made the center of both paper jig pieces the same size, you wouldn’t be able to fold them, especially once you had the fabric welt in there.

I’ll talk more about bend allowance (aka “turn of cloth”) as we go along because it’s critical when dealing with collars and facings. A lot of people have trouble with facings and they never have a clue why. Usually it’s because they did what the book said and made the facing to match its companion piece exactly. Well, exactly may be right in the book but it doesn’t allow for bend allowance. One of these days, I have got to write a production pattern making book.

Entries in this series (links open in a new window):
Zippered welt pockets
Welt-Reece machine operations
Marking & Cutting
Welt and paper jig
Welt pocket construction

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