āo tū yìn shuā
embossing
die stamping
凹
āo
concave; depressed; sunken; indented; female (connector etc)
凸
tū
to stick out; protruding; convex; male (connector etc)
印
yìn
abbr. for 印度[Yin4 du4], India
刷
shuā
a brush
