3D printing? I know NOTHING about it, but have heard of people re-sizing files.
Could that be done e.g. from 28mm to 40mm?
technically yes - although most sellers I've contacted in this context have been loathe to do so (in the 'can't be bothered to answer' sense of 'loathe').
Some have tho' - so, I as say, certainly feasible. Of course, prices have increased accordingly.
I've no experience of using 3-d print files or printers - there may well be good reasons why, subjectively, scaling up (or down) is to be avoided (i.e. extra work in terms of adusting the 'supports' etc? dunno ...).
***just been 'chatting' with a good guy on etsy (crisisactorminis) who's scaled stuff up for me in the past.
was looking at some figs for silver bayonet in 40mm, and he was explaining that most of the figures in question have relatively low polygon counts and, having been designed to be printed at 28mm, will start to show said limitation as the size goes up ...
so there can be technical reasons why some sculpts aren't really suitable for scaling-up.
I guess at the sculptor's end, it is possible, if not in fact straight-forward depending on the software, to scale-up sculpts - but not always, it would seem, at a printer's end, whether offering products commercially or not.
I'd kind of assumed that sculpting software worked in an equivalent way to vector drawing - i.e. infinitely scale-able without loss of resolution, but not so it would appear (in all cases anyway).