A #10 graver with six lines is about 1.1mm. Checking around with Rio
Grande, Otto Frei, Contenti, etc. you should be able to find one. I
prefer the bent liners over the straight as there is less tendency
for slipping. But it is probably a matter of individual preference
and how a person learns the skill initially. Feel free to contact me
off line with any other questions.
All the best,
JNB Jewelry Studio