10-15 mm seems quite large. Is it 1.0-1.5 mm? If so, you are probably
referring to the process called granulation, which is typically the
fusing of small silver balls to a back sheet (or similar). If you
search granulation on orchid web site, you’ll find lots of info. My
personal preference is granulation with Argentium, instead of fine
silver. Make the granules by balling up small pieces of Argentium.
Clean the destination surface, properly support the piece (Argentium
sags), position the granules, flux, and put the torch to it. Watch
for the “flash” or the “glistening” and you’re done. Practice a
couple times and you’ll be a pro.