Merlin's Protector

This site shows you how to protect your pinball machine playfields at an in/out hole or orb. It is only applicable where you have ball guides or posts near by to secure the plastic. I am currently using this technique on Medieval Madness and Star Trek TNG.
It is simple and effective, and best of all it's removable.
The plastic I use is 0.020" (1 mm) clear PETG. This type of plastic can be usually be found at your local sign fabricating shop. You can also use 0.020" Polycarbonate, but it is more expensive, and harder to find. It can be cut with scissors, scroll saw, or Roto-Zip.
The basic technique is to strip the PF around the in/out hole, and cut the plastic to size using the ball rail screws and posts to hold the plastic in place.
Below are pictures from my MM.

Strip area around hole. Notice the damage to the paint.

Repair paint damage with a sharpie or acrylic paint.

Trace your hole pattern for the main hole and the screw holes.
Try and use as many screw holes as possible to hold the plastic down flat. Then just cut and drill your pattern.

Check the alignment of your pattern and make any final adjustments.

Re-install your playfield parts. Keep the plastic stretched a little so it will stay flat.
Notice that I used black felt on my scoop to help the ball fall into the hole.

Done and barely noticable! No more wear.