Looks pretty roached from the pictures...it will never be perfec.....well at least with my paint talent....I have touched up some wall hanger back glasses....I used oneshot and a brush.....actually looks pretty good

fixing a backglass is really hard because you have to paint backwards, plus most are backsprayed. Best way to fix it is scan it, fix it in photoshop, then get translite printed (and re-use the backglass after you've stripped all the paint). Since this is a home version, I doubt that's going to be worth it?

It's worth it if they are satisfied with the final product. what's it matter if it's a "home version" or not?

it's fixin to be wall art. find a replacement. you know someone has one.

See other thread:
http://pinside.com/pinball/forum/topic/my-sons-first-shop-job

He plans on selling it at expo. If he were keeping it, of course it's worth it. If he's selling it, not going to be worth the investment

Jon at a minimum I would triple thick the backglass to keep it from flaking more

I agree. Purchase the TOP tape #1 and #2. They have some good tips on backglass touch up

My two cents worth:

If it were mine, I'd repair it as good as possible since there isn't any perfect and cheap solutions. This is how I'd do it. I assume the devil character is illuminated in the game along with his yellow "swipes", and the surrounding area around him is masked so the light will not pass through.

1.
I'd take some pictures on a medium that I can take into a store, like a cell phone. The subject in the photos aren't the artwork itself but the colors used and try to find an acceptable match at the art store. I'd use either enamel or a heavy body acrylic. I'd also pick up a small brush, and another one that has a tiny end for small areas. I would also pick up the blackest paint they sell. Not a sharpie pen but black paint you can blob on thick.
2.
I would position the glass front side down and paint side up on a table and let the artwork to repair hang over the edge of the table. (but not so the glass can fall)
Then I'd position a light on the floor underneath the glass so light will pass through the glass and plainly display which areas are masked and which side are not masked. The non-masked areas will illuminate with the light and the non-masked areas will not pass light except which escapes through the cracks in the paint. I'd dim the room light to see the difference if necessary.
3.
The masked areas are easiest so I'd start there.
The idea in this step is to know where one color ends and another one begins while working on the back side of the glass. I noticed a patch of blue artwork abuts the orange behind the character. I don't know, but I'll assume both are masked areas. I'd dab a small amount of orange on the brush tip and mark every crack that crosses that line between orange/blue artwork so you don't end up painting orange in the blue area and vice versa. Maybe put a dab of blue on the other side of the line next to the orange for further reference.
4.
With the light shining underneath so you don't paint any illuminated areas, I'd paint orange in every crack in the orange areas. I'd make it thick so the light doesn't pass very much through it, dabbing it on thicker in areas which have larger sections of missing paint.
I'd do the same for the blue (and any other masked colors with cracks with the appropriate color) making sure that I fully cover the cracks right up and even to the edge of (but not into) an unmasked area.
Note:
I assume the yellow areas are non-masked. But they have a thin, fine black border which is likely masked. Therefore I'd leave just a tiny bit unpainted so not to put any into that fine black border.

See my photo "Matching white and blue" for an example on my Space Mission.
5.
I'd let the paint dry overnight.
Then I'd set the underside light again to plainly show the illuminated areas. I'd apply the black very liberally over all the lines I previously painted to completely block any light from passing through. Dab it on thick if you must.
If there is illuminated letters and/or numbers shining through the masked areas I'd use the smallest brush with a magnifying lens (if necessary) with a lightly loaded brush to touch up the mask around the letters/numbers... or even rebuild the letters/numbers mask if the original paint is completely gone. I'd also use the smallest brush to paint the mask right up to the edge of the glowing yellow color. That will restore the fine black border again.
I'd look at the glass from all angles and make sure there's no pin holes which allow light to pass through the mask. Once done I'd let it dry overnight.
6.
Then I'd try and fix the illuminated areas. I would also need to fully accept that the repair will not be perfect, it may look reasonably bad but definitely better than before. It's a mindset to embrace- and if it turns out alright then I would be proud of it. This is somewhat artists work so I would not hurry through it.

The most noticeable defects are (1) Lightbulb glare through unpainted glass, (2) Unpainted areas where the board behind the glass is seen, (3) Areas of breach where two highly contrasting colors meet... such as the underarm area in your character where the crack(s) have ran, breaking the black line(s).

Since the light is shining from below, it is plainly seen which colors go where. Also know that what ever you paint in the illuminated areas, less light will pass through the area causing it to appear darker on the glass. Knowing that, it may be possible to fake a new artwork while fixing holes or cracks. The main idea is to cover the glass with a thin layer of paint as possible to minimize the darker areas.
It is also extremely important to understand which way to paint. Which way to stroke your brush. I'd start with black with a brush that is NOT saturated with paint. I'd dip the tip of the fine brush in the black paint, then wipe a bit off on a paper first. A few trials and you'll know how wet/dry the brush should be.

For example, look at the armpit of the character in your photo. See where the black lines are breached with a crack. I'd dab a bit of black paint into the crack and try to feather the edges, stroking the brush along the existing black line(s). I'd do a small area first then flip the glass over so the light on the floor is shining properly and check if it's OK for the black area I've done. If so, I'd do exactly the same process for every black line with a breached crack.

If there are areas where paint is simply missing like the spot on the character's chest then I'd put on my artists hat and be creative, rejoining the existing black lines.

7.
I'd do the colored areas next keeping in mind to use as little paint as possible, as thinly as possible. The idea is NOT to get good coverage. The primary goal is to simply prevent the #1 problem of light bulb glare and seeing the panel behind the glass. Not much paint is required to do that.

Again put on your artists hat. You've learned by now how dry/wet the brush should be so use the same practice.
If you simply dab paint in the cracked/missing areas it is confusing to the eye and will always look terrible.
The trick is to create "shaded" areas in places to repair. The character has muscles and a sort of shading effect can be made, essentially covering up the cracks and blank areas and create new muscles.

For the areas of the character's yellow "swipes", always paint in the direction of the swipe. Never perpendicular to it. Light tone colors will show the most shade from new paint. Keep that in mind when you are working in areas such as the yellow and judge for yourself if a particular crack really truly needs fixing. For example maybe there's not a light bulb behind that individual paint crack so no chance to see lightbulb glare. I'd consider leaving those areas alone.

White is the hardest. I'd leave those areas alone if at all possible.

When working in the illuminated areas:
*Do the black trim outlines before working with color.
*Always keep in mind to use little paint as possible. The primary idea is to block lightbulb glare.
*Always paint/stroke to the flow of the artwork.
*Avoid making hard edges. Feather them out a bit.

*Above all, expect the end result to be terrible and awful. That way you'll end up with imperfection and be very proud of the job you did, and the dramatic improvement achieved.

I've photo-shopped your image as an example of what I mean. I am pretty sure that an end result could be pretty close to it. Does it look original? Does it look fabulous? Is it great? In all accounts, no. Not by a long shot.

But I think it looks better than before and you won't get those lightbulb glares through it. I guarantee that you'll like the dramatic improvement after you've fixed just the mask alone!

If it were mine I'd tripple thick after the repair is finished so it's all sealed in place.

Matching-white-and-blue.jpg 6-R.jpg face.jpg

^^ Holy crap, great rundown. Very thorough. I'll use your advice on an incoming Gorgar.

Nice write up, mr fury. Very detailed and thorough as we've come to expect!

I have a couple of BG's that need a little TLC (one needs a LOT) that I plan on working on over the winter.

This will be of great help.

Thank you, sir.

Hi Steve, I am interested in repairing my flaked backglass as well. Could you please clarify in #2, which portion is masked vs. non-masked?

And, I read somewhere to triple-thick it before painting, so that the painter's mistakes can be fixed, and redone. What do you think of this?

Lastly, my glass has a large bubble of paint, maybe 3-4 inches. What is the best way to handle this?

Thank you!
Sky

Hi Skybug.

Masked portions of the glass will not allow any light to pass through at all. If the paint is flaking in those areas it can really be noticeable. Those are the easiest to fix. Match the color(s) on the effected area of the glass and apply a few thick layers of black on the backside to block the light.

The translucent areas are most difficult especially where the original paint is a gradient or lighter color. Using a paint brush in those areas will almost always stand out. You will see the brush strokes. Some translucent areas with a lot of shading and "business" to it can sometimes be faked using a brush, trying to keep within the original theme of the art.
I am NOT experienced with airbrush yet I purchased a cheap $65 Michaels airbrush and successfully fixed two backglasses where a regular brush simply wouldn't work in the translucent areas. No not artistically perfect and not original but who's to know?