It means teacher — and as a suffix, it's a job licence.

What a Japanese person actually thinks
Reads as an occupational suffix waiting for its first half. Alone it's incomplete in the same way English '-ist' would be.

Meaning

Literally: master; teacher
Actually: A teacher or master. Mostly lives as a suffix denoting a licensed profession: 医師 (doctor), 美容師 (hairdresser), 調理師 (chef), 教師 (teacher).

Scores

Naturalness●●●●●

Rarely stands alone in modern Japanese.

Coolness●●●●●

Decent character. The fragment problem is what costs it.

Watch out

mediumAlso, wearing 'MASTER' is a claim about your rank relative to other people — an odd thing to assert unprompted.

Get this instead

師範 shihan
master instructor (in a martial art)

If you actually hold the rank, this is the real title.
道 michi / dō
the way; a discipline

Says you practise something without claiming to have mastered it.

On skin

師

Orientation: either

Brush.