I don’t know anything about enameling, but I do have a fair amount
of knowledge on leaded/ full leaded crystal ware(Waterford, Lalique,
Fostoria etc). Crystal termed as leaded has a lead content of no more
than 23%. Full leaded has 32%. Full leaded is the most sparkly kind,
hence the higher grade and much more expensive. 32% is the max
content or else the glass turns grey.