In response to your query, bimetal products have a sterling base
(they come in 1mm and .5mm gauge), with a layer of 22k or 18k gold
fused on top. Although I can’t tell you the exact thickness, it is
possible to roll it a couple of times and do 2 to 3 soldering
stages. If you do too many more, I find the colour of the gold dulls
and this is particularly so with 18k so I don’t tend to use that one.
Hope this helps!!
Christel van der Laan