A man’s 18th century shirt requires about 3 yards of modern linen but it is really a measurement from the shoulder to the knee x2 plus the length of the sleeve. Most boy’s shirts were made of off white linen but boy’s of the lower sort wore natural unbleached linen shirts. Sailors & civilian laboring boys also wore blue check linen shirts. Young gentleman (when wearing a stock at the neck) wore finer & whiter linen shirts with ruffles which require a quarter yard of fine linen or muslin but poorer boys also had a cheaper quality of finer linen ruffles at the bosom slit, collar & sometimes at the wrist &/or wrist slit. The latest research suggests most preadolescent boys wore a ruffled bosom slit the ruffle of which extended all the way around the collar & therefore the boy wore no other neckwear but this pattern lacks this easy modification. You can read about this research here.
Notions required include a spool of 60/2 linen thread in white, off white or unbleached to match the shirt, today’s research suggests preadolescent boy’s shirts closed at the collar with a 1/4 yard of 1/2″ black silk ribbon although this pattern calls for 1, 2 thread buttons on the collar & sleeve buttons at the wrist (although this pattern calls for 1 thread button at each wrist which may have been more common in c. 1800-1730).
For winter wear, shirts were frequently made of natural white wool flannel (check & stripe wool flannel was also used but is very difficult to find today) which may be substituted for the linen above. Don’t be fooled, this flannel is soft next to the skin & really helps when it’s cold out!