I use Posca paint pens for all my black key lines etc..
They are great, I use the .07mm tip and for straight lines but be careful, I use a ruler but make sure the curved side is down. A standard ruler has a completely flat side (back) and the front where the measures are has a curve, make sure this side is down or it will pull the ink. Then once you have done all your black lines let dry overnight then use a small artists paint brush and lightly brush all the black lines with clear to seal it before you apply the first coat. If you don't seal it first it can drag into the clear when brushing. May not happen if you spray but if using a foam brush etc this is a must. Doing it this way will give you great keylines. You can also use a circle stencil for the inserts but you must raise the plastic stencil slightly so as it is not touching the playfield, using a few blobs of hot glue on your circle stencil to give it some lift (only a mil or 2) will do the trick. Then lift the stencil straight up when finished, I use bluetack blobs on the top side of the circle stencil to lift it off with.
If using KBS Clear Coat try out these applicators from Bunnings, I have had a real win with these and recommend them highly, I cut in half for better control. Also thin to 30% for better leveling.
http://www.bunnings.com.au/shur-line-handi-painter-_p1670161Good luck with it..
Cheers: Brettski... :)
