Glenn, Embroidered grenadier caps of the 18th century can be really colorful but are often not correct when depicted in miniature. To get your model as accurate as possible it's great to have a piece(s) of material culture
(period artifacts/ militaria what have you) to use in getting it right. Sadly I've seen few pictures of actual caps, but they do exist and can help provide a sculptor with the means to get the cap more correct looking.
The period paintings of David Morier are a great source of reference for caps, but I would not use these as a sole reference. The caps in Morier's paintings appear to be somewhat taller than actual surviving caps. Additionally, the details appear to be neater than what is seen in actual enlisted men's caps. I think a lot of folks use the series of grenadier paintings to model their sculpted caps. I'm not sure of the source but a recent reconstruction of a grenadier cap could have been based on Morier's work.
http://www.planetfigure.com/forums/showthread.php?t=24302
While the cap is well done and the details are all there it looks more like an embossed cap like you see worn by German troops of the 18th CENTURY
(see picture 1) rather than one that was embroidered. In comparison to an actual cap the details look far too neat and precise.
1. Hessian metal cap.
For some reason this image loaded last and is at the bottom of the page.
2. A typical other ranks cap from the 49th Regiment of Foot. This cap is a great example of not only the workmanship of these caps but also the somewhat crude representation of things such as the horse and lettering on the front of the cap. Note the regimental number on the back of the cap.
3. This officer's cap from the 43rd Regiment of Foot contrast greatly with the enlistedman's cap.The details are a lot sharper.
4. This illustration of a cap from the 12th Regiment of Foot looks more like an actual cap rather than it being a modern reconstruction that just used the real thing as more of a guide only to end up looking neater than it was in life.
5. 21st or Royal Fusiliers cap. I do not have an illustration showing the back of the cap. On the blue front is the Circlet of the Order of Thistle- a pink thistle with greenish leaves all within the Circlet bearing the words
Nemo Me Impune Lacessit. The tuft at the top of the cap was blue and white. The band around the cap would be blue with white piping/ trim. The upright "bag" portion would be red with white piping/ trim. The few details on the back of the cap can possibly be found out by a broader search or "guesswork" based on surviving caps or period art. I'm unsure as to what type of design or scrollwork decorates the sides. I would probably do the grenade device on the back white but it's up to you as to how you wanted it numbered be it a 21 or in Roman numerals. The last two illustrations were taken from an excellent article on British Grenadier caps in the
January / February 1987 issues of
Military Modelling.