What does "Japaning" mean?
 

I see this reference in some posts, I'm new to vintage machines and do not know what ppl are referencing. Can someone clarify. Thanks.

Japanning is the black finish on antique sewing machines. It's asphaltum and linseed oil. The bare machine heads were dipped in it, then baked. This happened several times, then decals were applied, and varnished over.

Bare metal was often japanned for protection. That it looked nice was bonus! My dad has some of Grandad's tools that were japanned. There's a recipe running around on the internet for making your own japanning so you can restore old tools.

MrsBoats is absolutely right.