Silk Screen Pin is to make patterns be silk screen printed on the surface of hard enamel pin. After silk screen print the pin surface is still flat and smooth.
For Hard Enamel pin, there will be metal lines around each enamel color. However there will be no metal lines around silk screen print pattern.
It is wildly used to show small & detailed patterns such as bubbles in ocean, These mentioned parts are quite difficult or not suitable for hard enamel process then silk screen print helps.