Trays were cut to size with shears, the outer edge hammered to about half its original thickness, the edge decoration punched out, the form was then tapped out over a pattern, and the edge inclined to a desired angle.

Tinwares were cut into shapes, soldered or welded, (overlapping seams may be seen), then the article was degreased in acidic fermented rye liquor, the first coat vanish was applied, high temperature heated and polished.

The finish was transparent but had a brown staining colour, which, when used over silver leaf designs, tended to give a rich golden brown tone simulating gilding.

The characteristic black Japan was produced by increasing the proportion of coal tar in the varnish.

In 1801, the processing was described as "very simple but tedious". Given the number of individual stages of the process, each item must have taken some time to complete, hence its expense.