Most of you have experienced a pair of trousers developing holes and tears in the crotch, probably at the least convenient time. Tailors have developed a way to help prevent these issues, called staying the fork. Since this area of the trousers takes the most stress, it’s important to reinforce it. The stay also prevents the bias from stretching in this area, and offers a little more protection from moisture.
To begin, cut two 7 by 7 inch squares of either linen or cotton. I’m using 100% cotton Silesia, but any stout cotton should suffice. Linen is recommended in the Tailor’s Guide, The Making and Repairing of Trousers, Vests, and Coats, from 1901. The only benefit from using linen would be that it’s a little cooler.
Each square is then folded along the diagonal, and the fold is then pressed into a curve. Hold onto the tip of the triangle, then with the iron, work along the diagonal, stretching the fabric as you go. Illustrated are the two stays, one before the ironwork, and the other with the curve completed.
Next, lay the stays on the wrong side of each fork, with the folded edge toward the body side of the fabric and baste along the edges to hold in place. The stay should be centered on the fork, with equal amounts of the stay above and below.
Trim off the excess fabric.
You can see how the stay helps prevent stretching. The line in the photo illustrates the direction of the bias on the wool. But that same line corresponds to the straight grain of the cotton stay.
There are several ways to finish the stay from this point. One is to just leave it as is, and have it secured when the leg and seat seams are sewn together. The second way, which is my preferred method, is to whip stitch the raw edges. It prevents fraying, and seems a little more finished, to me. A third way I just uncovered, is to leave the raw edge, and whip stitch the folded edge down.
Here is a pair of dress trousers from around 1910 I was lucky enough to find (along with vest, and tailcoat!). You can clearly see the fork stay in the photo. They used some very nice pocketing for theirs, but alas, it’s hard to find fabric that nice now. Notice the finishing details. On one side, it is unfinished, and the other side, they whip stitched the folded edge down.
I believe details like this are what sets nice trousers apart from ready to wear, or ‘sutler quality’ trousers. I have not yet documented their use to the 1860s, but it is up to the client to decide if they want the stayed fork or not. CVFM, whose trousers are featured in this post, wanted longer lasting trousers, and were more concerned with durability than authenticity. If anybody has documentation on when the stays started appearing, please let me know!