I think this has been kept away from, because it's so damn expensive to have a sheet of glass custom cut/drilled to allow for your bumpers, drop-targets, posts and everything else to be mounted.....
Then the thickness of the glass means all the mechanics will no longer 'reach' where they should, so a LOT of routing out underneath the wooden playfield needs to be done for the bumpers and targets can still poke up high enough for the (now) higher level of the glass sheet (which adds 3-6mm thickness onto your playfield).
Then after routing out everything under your playfield (or simply gutting the playfield and running it thru a plane to remove 3-6mm thickness) you'll then need to use shorter screws, or leave enough of the original wood in place around all the screw holes.....
Glass may eventually mark and streak from ball-skid, but perhaps polishing with something SUPER shiney/slippery polish will help prevent marking....
You'd wanna use brand new balls, and clean/polish ALL your underside ball guides and ramps.....everything that can contaminate the ball with carbon dust and grime must be removed so there's less chance of the ball marking the glass... (this also applies to regular upkeep anyway).
Hardened glass may solve the marking problem, but more costly....
Ball-drops from when the ball bounces off items, or simply 'drops' from an upper level down onto the playfield may also cause chipping & marking over time....
Perspex is out of the question, it'll scuff and streak in an hour of gameplay, plus the heat from all the lamps may cause warping problem too in time.
kinda gets messy huh?
I have a design for a glass/top playfield (easily removable for cleaning/replacement) but that's under wraps at the moment
MM.
