Undercollars Part One - Cut

Undercollars may not, and should not, show in a finished garment, but they often are the factor that makes or breaks it.

Basically, there are two essential considerations regarding undercollars - Cut and Grain.

Today I'll do my best to explain how to best cut an undercollar to take advantage of the principle of turn-of-cloth. Turn-of-cloth is what they ("they", all-knowing magnificent wise ones of sewing I guess, or maybe just "they" who've done it wrong before and learned the hard way) call the simple geometric fact that when two equal length anythings are curled one around the other, the outer anything will not reach the same point as the inner anything b/c it travels around the longer arc circumference. How's that for clear as mud? It's intuitive, but hard to put into words. So...pics...

Here are two magazines. They are the same size and shape. But when one is curled around the other, the edges don't meet up. That is because the outer magazine is traveling around a longer arc. It has further to go b/c it's on the outside of the arc (which is part of a bigger circle)...but it's the same size, so it stops sooner. Here are two pieces of paper. They are the same size and shape though different colors for illustration. When they are curved around one another the outer layer, again, does not meet the inner b/c it has a longer route to travel. The paper is thinner though, so their arcs are closer together and the difference in where they end is less pronounced. (See the bit of yellow paper underneath peeking out?)The same goes for fabric. Thick pieces of fabric, cut to the same size but curled over eachother, will end up farther apart than thin pieces of fabric treated the same way.

Here are two collar pieces I've cut from a coat's uppercollar pattern. The brown is melton wool (heavy coating wool) and the bottom is black wide wale corduroy. I've pinned them together at the neck edge, where they'll be sewn into the neckline. Here they are flat. Flat is fine if you intend to forever wear your collar turned up like The Fonz.But here are the same pinned together collar pieces shaped into an actual 3-D collar. Yikes! See all that excess black undercollar fabric? That will do several really icky things. It'll bunch up underneath the collar. It'll peek out to the front of the garment. And it'll cause the collar tips to flip up and outward mimicking the Flying Nun's hat.This is why many quality patterns will include a separate undercollar pattern. Here are the collar patterns from Vogue 7467, under collar placed on top of upper collar, necklines exactly lined up. Note the undercollar is smaller on the outer edges. (You will also note that the undercollar has a CB seam allowance whereas the upper collar is cut on the fold, and that has to do with Part Two's topic - Grain of undercollars.)
This is an appropriate cut for suiting wools. However, had I decided to use this pattern for coating wool, I would increase the difference b/w the two collar pieces by either adding more to the upper or trimming the undercollar pattern piece. How much? Well, doing a test like that I've shown you with the brown coating and corduroy, but using the actual garment fabrics, will tell you just how much smaller the undercollar needs to be. Simply measure the distance it peeks out after you've pinned it in place and curved it into collar shape.

Similarly, if you are working with a pattern that provides only one collar piece with instructions to "cut two on fold" (one for upper and one for lower collars) then you can easily create a better undercollar pattern.

Simply stated, you must trace the collar pattern, trim the outer edges as much as determined in your test, trimming a bit more around the back than at the front edges.

Then, if you really want a professional looking collar, you will also add a seam allowance to the undercollar's CB and change its grainline to bias. I'll talk more on the benefit of bias undercollars and how to cut them tomorrow. If I don't get some work done here I'm going to be sorry tomorrow when clients come knocking!