Once you move the t-shirt, youâll have a basic shirt outline, like the one you see below. Draw a slightly lower neckline curve for the front of the shirt. Also draw a straight line from the armpit to the neckline, as you see below. Cut the pattern piece out, and cut it apart at the armpit-neck line (1st photo below). The next step is optional, but I think it gives the shirt a little better fit.
cahier. 1  Bookbinding. a number of sheets of paper or leaves of a book placed together, as for binding. 2  a report of the proceedings of any body: A cahier of the committee was presented to the legislature. ( 3 italics) French.
The word tuyau is used in French nowadays to designate the cables (fibre or other) that transport data. Maitres des tuyaux is a common enough ready made expression en French to designate those who master those means of communication (Google, Facebook ou Amazon, named in the quote). You are misreading the text you refer to.