I have been an apprentice for 2 years now and it is time for me to begin to learn how to finish a jacket. This includes working on the collar and putting in the sleeves. These two processes take a lot of patience and deep breaths.
Once the shoulders have been closed and pressed, I make a start on the undercollar. Starting at the back of the neck, I baste it on so that it stays put and cannot move around. The undercollar seam must match the back seam of the jacket. I then baste it around the back neck working in fullness on the undercollar edge as I move around to the shoulder and finish one and a half inches down from the shoulder. This forms the back neck and collar stand. At this point the collar is manoeuvred so that you can lay it flat and finish basting round to the lapel letting the collar fall where it feels most comfortable.
My teacher, John will come and check and make sure that the collar is sitting in the right position. She makes sure that it has a nice, smooth run over the shoulder and that it is neither too tight nor too loose. This is extremely important as every part of the jacket hangs off of the collar and therefore, if the collar is too tight, the lapel will roll too low and if the collar is too loose, it will roll the lapel too high.
A lot of the work involved with the undercollar is about using your eye to check if it is right so experience and practice is the only way forward!