I currently do sterling silver casting, and I have read in many places to use 50% old (e.g old sprue buttons) and 50% new e.g. casting grain.
My question is…..
Is there any difference between casting grain, and off cuts of silver sheet/wire (both bought from Cooksons of course .
Also would heating up the silver sheet affect if – e.g. If I soldered two pieces of sheet together , and then cut off some of the sheet (that did not have any solder on it) would this silver that has been heated to soldering temperature be the same as sheet silver that has not been heated – and how would these compare to casting grain.

Thanks in advance Paul