Contemporary Documentation of Interest
Cuthberston, Bennet. A System for the Complete Interior Management and Oeconomy of a Battalion of Infantry, London; J. Millas, 1779, p 58-59:
"The shirts given to the Non-commission-officers and Soldiers, as small mounting, on the British establishment, fromt the indifference of the work, can be of little use, unless taken to pieces and made up properly, with a ruffle at the bosom, which is an ornament, that should always be added to a Soldier's shirt:..."; "It is a mistaken oeconomy in Officers, to buy very coarse linen for their Soldiers shirts; that of one shilling and four pence a yard, is the cheapest, from which any material service can be expected; four shirts (three of which should be perfectly good_ are as few as a Soldier can dispense with, to support that neatness which at all times should distinguish him:... care must be taken, that they are worked both neat and strong, with buttons at the collar, which should not be allowed to turn over the stock, above half an inch; the ruffle at the bosom, need not exceed two inches in breadth, and it will be an addition to the look of the sleeves (which otherwise appear quite naked) to ornament their slits, with half and inch ruffle; eight pence a piece is a sufficient allowance for shirts made agreeable to these directions, nor should the women be ever suffered to demand a farthing more."
Here's a close-up from a screencap of Mary Bryant, showing a Marine with a ruffled shirt: