A lot of people have asked me how I make the decals I use as part of my game restorations, so here is some info that might be helpful. Pictured here are some of the playfield overlays I created for my Haunted House restoration.

I use white waterproof inkjet-printable vinyl from papilio.com. It is a permanent self-adhesive material that produces excellent quality results.
For lamination after printing, I use Avery 73603 self-adhesive laminating sheets available at Staples. It is essentially "mylar" and serves to protect the printed surface against wear.

First, you need artwork! There are tons of image files already available online, from other pin collectors, using photos from NOS playfields, scanning images, and even re-creating artwork using photos of original images as reference.
For example, this is a hi-res photo of a NOS lower playfield for Haunted House that was graciously provided to me by the playfield owner. Once sized correctly, then it was just a matter of adjusting the printed colors to match my playfield before I printed the overlays.

Pictured here are decals I removed from the coin door of my Black Knight to clean up and reproduce. These were factory-applied but had gotten messed up over the years. Typically, I'll use a hair dryer to heat them up for easy removal. However, these were stubborn and required removal using a razor blade. Just catch an edge with the blade and slowly work your way behind the decal.

After scanning in the original images, I use photo-editing software to repair them. My program of choice for this is Photoshop, but there are other programs that will work just as well.

Once I've prepared the artwork, I then print it onto the vinyl media using an Epson 4600 inkjet printer. Believe me, it's nothing special but it gets the job done! I usually do a test run on regular paper to check for color accuracy, and make adjustments if need be before running a final print on the vinyl.

Once the ink has dried after 5-10 minutes, I laminate the vinyl using the Avery product. Once applied, I use something with a rounded edge (here I'm using the curved end of a Sharpie) to "rub out" the lamination. What this does is remove the haziness of the adhesive. The end result is a decal with rich color and crystal-clear detail!

Then, just trim to size, peel off the backing and apply!
Here are the new decals installed on the coin door of my Black Knight. They turned out great and really help make the door look new again!

The vinyl media is also good for creating drop target decals like on Black Knight...

...and playfield overlays as shown here for the pop bumpers on Haunted House.

I also used it for making stand-up target decals for my Firepower...

...and other miscellaneous decals like the "Caution" decal on this lockdown bracket.