Wig & Pen offer a lot of their books in various e-Formats.
https://www.pen-and-sword.co.uk/ebooks/313/Military/order/title/asc
Very useful for those marginal buys that you're not quite sure about, but also offer the ability to zoom in (best with PDFs) which gives extra value if you want to use pics as references (in fact I got both the hard copy and PDF of the Absolon Japanese Armour book for that very reason-though at a lower price than currently)
A full list is here.
Nap ones include Dawson's superb ref works (lots of photos of the real things):
https://www.pen-and-sword.co.uk/Napoleons-Imperial-Guard-Uniforms-and-Equipment-Kindle/p/17390
https://www.pen-and-sword.co.uk/Napoleons-Imperial-Guard-Uniforms-and-Equipment-Kindle/p/17307
https://www.pen-and-sword.co.uk/Napoleons-Waterloo-Army-Kindle/p/18334
The last is great, but can be bought cheaper (and I assume legit). I got mine at £8.99 here:
https://www.ebooks.com/en-gb/searchapp/searchresults.net?term=Napoleon's Waterloo Army
This is a weird one (based on Bardin's Regs) : few illustrations (it's not a uniformology) but great if you want the nitty gritty about how many pairs of underdrawers a soldier had*, what order they had to pack their haversack in, how much they paid into their mess fund, the precise tariff of punishments for their various crimes and misdemeanours and so on (and I'm only halfway through it so far):
https://www.pen-and-sword.co.uk/Napoleons-Infantry-Handbook-Kindle/p/10698
... and a couple for Nap:
https://www.pen-and-sword.co.uk/British-Military-Medals-Second-Edition-Paperback/p/18479
https://www.pen-and-sword.co.uk/Gallantry-Medals-And-Decorations-Of-The-World-Kindle/p/8222
*Well since you ask, the answer is 'generally none' until 1812 as the culottes/pantalon had a sewn in linen lining instead (although some wimpish regiments did issue separate calecon/drawers). In 1812 they were issued with unlined pantalon and separate drawers which were then expected to last a year (it doesn't say if that's between washes as well).
