Does anyone know the relevance of '20 M' stamped on to silver/ plate?

[dlmuk]

Hi there

I have a silver or silver plate basin from a French Necessaire de Voyage from around 1820. On the rim it has been stamped with '20' and an 'M'. Does anyone know what this might refer to?

Many thanks

[Goldstein]

Hi dlmuk -

20M (20 Micron) is the silverlayer "thickness" (silver-plating) on your object. More micron = better quality and durability.

Regards
Goldstein

[dlmuk]

Thank you so much for shedding light on this for me - I really appreciate it