This is really a continuation of my thread here:
https://pinside.com/pinball/forum/topic/my-new-target-pool-project
I thought this might need an extension thread.

Quick review: I am in the process of restoring a 1969 Target pool that has been sitting outside under a carport in the hot/humid Georgia USA summers and cold damp winters for a number of years. The general restore is mostly finished and I am about to do the back glass.
I can have a new reproduction back glass for $230... and I am sure it is of excellent quality but the price is prohibitive. I might get one of those someday but I am going to try and fix what I have for now.
I have fixed a few BG's before.

Lets see what can be done with this one. Who knows maybe it will turn out alright and maybe a total disaster. Anyway this is what I start out with. I uploaded a fairly large size:
Glass Original.jpg

Heat/cold expansion and destructive padding tape are some common problems. Those were issues here, and I had also noticed the latch bar inside the back of the head latched -really- tight against the glass. Why? I pulled out the glass and the latch more easily closed. Looking at the front of the head, I noticed a nice gap for the glass at the bottom but the top was being squeezed pretty tight:
Squeezed.jpg
No matter how good (or bad) I fixed the glass, this had to be fixed. It turns out the particle board had expanded (Got thicker). I wanted to stabilize it best I could and get it off the glass. Stabilizing was done first. I removed the board from the head and worked wood glue into the edges. Then I painted it white with a whole rattle can of Rust Oleum satin white enamel paint. I masked various areas (Score reel, sides, credit unit etc)... also filled every lamp socket with bad burned out bulbs so the sockets will remain unpainted:
Unpainted.jpg
Painted.jpg
You can see it also dramatically improves the light reflective properties which will be important later:
Painted,Lit.jpg

Next is fixing the latch.
The left diagram shows the original design. The middle is how the glass was being squeezed. The right is my fix:
1. Removed the latch screw. Filled the screw hole with glued-in hardwood wedges, then drilled a new hole just aft of the original.
2. Added a wood screw and a stack of washers to contact the stop brackets. The washers help keep the pressure off the screw and distribute any pressure. Washers were added until I got the right glass distance and latch operation.
3. (Not done yet) Add some stiff weather stripping to the very edge of the particle board, out of the image area to hold the glass against the cabinet face.
Mods.png
Screw.jpg
Washers.jpg
Rear.jpg
Hardware.jpg

Can anyone who has a target pool please snap a photo of this ladies face so I have an original to go by? Thanks in advance.
Face.png

I have some preparation to do, I hope to update this thread soon.

The original pad-tapes had crumbled as they do, down to paper thin. I removed by scraping them off as powder.

The rear locking lever required excessive force to latch, as it compressed the particle board against the glass. Adding new padding would provide a space between the glass and board but the force required to lock would be too much.

With the glass out the latch had a normal latching effort as it pressed against the stop brackets. A reasonable and normal space existed at the bottom of the board to the cabinet face. The particle board pressed against the face at the top (see pic).

Could also move the stop brackets back by relocating them.

I think that will work, thanks!

Thanks for the hi res pic.

A lot of people already know this about backglasses, but there are different layer features for different styles. I have noticed 3 basic features regarding ink layers.
1. Masked.
This is the easiest to fix because the final or top layer is a light blocking mask. It represents any non-illuminated areas on the glass. Most factory masks will look silvery gray when viewed on the back.
2. Hidden.
This feature is not visible on the front of the glass unless illuminated from the back. Typical use is the match numbers. It consists of a first thin layer of base color(s) directly on the glass that matches the surrounding artwork. Then a layer of light diffusing color shaped by the number or word (TILT). The feature is not masked.
3. Translucent.
You can see these on the front and light up as general illumination or indicators. The feature is usually a light colored ink/paint directly applied to the glass and never masked.

Damaged masked areas are almost always the easiest to fix. Really the only problem I find is color matching. If the repair is not a *very* dark color then it will often need a mask applied or else it will be translucent and thus an ugly repair, letting unwanted backlighting through. I use a thick layer of black for a mask. The repair paint can be applied by regular brush or air brush.

Hidden, and especially translucent repairs *must* be applied by air brush with the only exception of very small areas and lines. If you use a regular brush then the unavoidable brush strokes look terrible when back lit. The base color that is part of the surrounding artwork for a hidden feature must be thin as possible especially if its color is dark so the diffuser layer behind it can shine through. The diffuser on a hidden feature is the actual number or character seen on the front when illuminated.

-->I like to use Liquitex Titanium white for diffuser. It applies evenly and transfers light well.

I always apply the diffuser layer thin as possible for maximum light transfer.
It takes as much back light as possible to illuminate the diffuser paint. That's why I painted the head's wood insert white. I am most definitely NOT a fan of LED lighting on EM's. Period. But that's a debate elsewhere.

I began collecting the things I need this evening. It started by inspecting the damaged areas and noting what colors I'll need. You may be surprised how many colors are repeated in different areas on a backglass. For example on my back glass, the light brown ceiling, people's skin and the billiard rack are all the same brown.
Some colors like black and white I already had. I am not skilled at mixing colors so I took photos of the colors with my cell phone and took it to the art store and matched close as possible with their stock. My photos didn't concentrate on pictures or patterns but rather colors. Here, for example shows 7 colors (+generic black and white) to match:
colors.jpg
More such photos help cross-verify the selections in the store.
I noted the high reflectivity of the glass, that the darker colors are my target.

Tonight I set up most everything I'll need on a padded table.
Various tubes of colors both new, and stock I already had. I like Liquitex heavy body but other brands found in the store more closely matched my project. I'll see how the other brands do.

Other things are a heavy bowl to support the glass when overhang over the table, tape, paper, pencil, straight edge, pinpoint and broader brush, my cheap but trusty Badger 350 air brush, compressor, razor blades, mixing sticks and a color mixing wheel comes in handy.
I also have a #44 socket wired to a 6v 3a wall wart to test repairs while back lit. Also a bright LED trouble lamp to spot otherwise hidden ugly cracks and check translucent paint consistency. Also a magnifying glass for my poor vision and bright open space to work.

I stabilized the existing ink/paint with Tripple Thick last month.
stuff.jpg

I hope to start on this tomorrow evening. You'll get to see, step by step how I destroy this glass.

I began doing this tonight.
My goal here is -not- to recreate a perfect specimen of the original or reproduction. I'm not much of an artist. I am hoping to reduce the ugliness by filling in holes and cracks. If I end up with something better than what I started then I'll be happy.

I started by working on the pad tape damage on the top corners. These are masked areas so using a regular paint brush is appropriate:
Full glass original.jpg
The Gottlieb tape pad was black and bits of it were tripple-thicked right onto the glass. If I left it on then the repair would have had black sprinkles in it. So I carefully scraped it off of the light brown areas with a razor blade. I didn't want to scrape off the dark brown. Working on the back side, I couldn't tell the line where light brown met dark brown. I laid a strip of tape along the edge and could see the tape from the back as a guide on both sides (I must *never tape the back side):
Tape border.jpg
I had to mix some of my light brown paint with dark brown and some yellow for a reasonable match. These photos look pretty bad but it looks a lot better in person. So much better in a darkened room with low light. I could have scraped off that entire light brown stripe and repainted but.... eh... that's too much work.
I kept the tape in place as a guide for painting the back to keep the light brown from going into the dark brown region:
fr.jpg
Here is the back side painting for the two corners. I noticed cracks in the paint toward the top of the glass, areas of the same colors so I blotted some paint there:
rear l-r.jpg

In the dark brown areas, if I just simply painted dark brown there then it wouldn't look right for missing the black wood grain lines. Inspection of the artwork shows the bottom of the ceiling "beams" have a denser concentration of black lines. I again moved the tape to the line that represents the border of less/more dense lines as a guide and applied some black lines using a fine tip brush.
I will be applying the dark brown paint over the lines (as a layer) but want to let this dry overnight before doing so:
lines.jpg

I think those two corners look better filled in than the original holes (Still need to paint the dark brown). Again, the right corner looks better than the photo.. I could scrape the whole light brown line off and re-do if necessary but I want to move on:
20150723_233739.jpg

Gimp, a free opensource alternative to Photoshop.

Hmm... not sure how that will work.
Anyway I have an update, but first things first... Taken this morning after doing "business":
puppy.jpg

Ok, I mixed up the dark brown and painted on the back and it looks alright.

BTW I am only working on masked areas first since that's where all the big holes are. My tube of blue matches fairly well with the glass. A few holes filled. Another important thing to note is to fill all cracks with the appropriate color. Here I'm doing blue. Since these areas are all masked, I'll be putting a thick layer of Liquitex ivory black over any light leaks. Ivory black is 'bout as black as black can be and stops unwanted light transmission well.
Any cracks left open to the glass that is not painted the right color will show black with the mask. Ugly, crack shaped black lines that is. A photo of cracked and the repair:
Cracks1.jpg
I next wanted to fill the holes around the match numbers. The area is green billiard table and the color matched pretty well while the paint was wet. It darkened up somewhat after dry.
Notice the blotchiness of the paint. That is going to be alright as long as the paint is thick enough so not to let the mask show through to the front. The paint, as it lays on the glass is flat and will appear consistent with the mask backing. The match numbers and TILT are hidden features therefore I don't brush-paint over them else you will see brush strokes when lit.

I was fortunate to have enough of the match numbers visible to estimate their position and shape. I am not finished with these numbers and TILT... The will need to be air brushed later because they are illuminated:
Match.jpg

I had to touch up the black border of some billiard balls in the rack using the Ivory black on a fine brush. It took me a while for trial and error to come up with a reasonable color match for the rack's sand-colored background. The previous black border is the first layer of paint, and I was able to paint right over that layer with the sand color.

This area has a lot of different illumination points from all directions so I wanted to cover as much masked area as possible. The black mask would look terrible in this area should it get through to the glass so I was particularly careful to fill all cracks. I shined a light through the back to check and fix any "star" and crack light leaks:
Back cl.jpg

That's enough for tonight, here's how the back looks now:
Back.jpg

Here's how it is now.
My phone's camera seems to be making the color variations worse than they really are, although I wish the billiard table turned out a little better for a color miss-match. Other defects my camera is picking up and accentuating are general blotchy areas caused by the Tripple thick getting under the orginal paint (Between paint and glass). An example is the blue bottom of the billiard table. Those blotches are the tripple thick and can't really be seen in person.

I didn't expect reproduction quality, just a decent repaired glass. As I expected:
Now.jpg

Better, at least than holes:
original cl.jpg

There's a couple more large holes and the ladies mouth to fix before applying the main light blocking mask.
Once all that is dry then I'll start airbrushing the translucent areas that need fixing.

I've decided I can't live with the crappy billiard surface. I need to make it uniform so I'll be scraping it away and repainting with airbrush. I use the airbrush because of the hidden artwork. A regular brush would look terrible when illuminated.

Since correct placement of the hidden artwork is critical, I taped some stencil material to a large sheet of paper and aligned it to the bottom left corner of the glass.

Here is my stencil setup. Notice it's aligned to the corner of the glass:
20150725_091210.jpg

The marking on the stencils are not easy to see/verify so I slipped a sheet of paper behind to check them:
20150725_091229.jpg

I think it will take a while to scrape off all the billiard surface. This is the first time I'll be clearing such a large area. Wish me luck.

Ok I am happy with this one.

I scraped all the paint off the billiard surface and cleaned up the bare glass.
There are translucent images on the top and sides that are very close to where I will be spraying so I made a mask:
masks.jpg

I spent a little time mixing green and white to get an acceptable shade, then thinned it out for the air brush. The idea is to put a very thin paint layer for the first few coats to help prevent problems like fish eyes etc. I use the hair dryer between coats so the paint on the glass will dry faster than the paint in my airbrush (Prevents clogs).

The 15 pool balls are translucent and need to be masked. I measured the circles to be 1.25" diameter so I stopped at the hardware store and got 15 steel washers. I put tape on the rounded side and made a little handle out of the tape.

I could have just masked the entire triangle with cardboard and paper but I will eventually need to apply a thick Ivory black light-masking layer anyway around the pool balls so the washers will work excellent when I apply that mask.

Here I am ready to load the brush and get to work. I laid white paper behind the glass so I could judge the application of paint:
Ready.jpg

Here it is after the first few coats. My main concern is to get a smooth even consistency.
first.jpg

Afterward... Look OK so far...
done.jpg

Success....
front.jpg

I'll let this dry and begin cutting out the match and TILT stencils.
I may need to spray a thicker green build-up to hide the unlit characters. I mixed plenty of the green just in case!

What I did wasn't too complicated. I first scraped with paint side up. Since you can't see the image from the paint side, I only started in a known area (Around a match number) then flipped the glass around to see what I was doing (Scraping upside down).

I used a new regular razor blade and worked slowly, sometimes with just the corner of it. It helped to cut the paint along the line but if the original ink/paint wasn't good then it chipped causing a jagged line.
My work around was to cut a bit of a distance from the line. Most of the artwork has a black border line. Most of the time the chipped areas were black border lines anyway so I was able to touch it up with ivory black paint.

It has been a learning experience.

Now that I had the base green down, how thick should it be? Not thick enough and the unlit match and TILT will show too much and they won't show well at all if it is too thick.

My solution was to first put the stencil in place and tape white strips to the bottom underside of the glass. I will be painting white characters and the white strips give me a reference how they may look. The strips also help me judge the paint consistency across what will be the faces of the characters.
1.Stencil Strips.jpg
So I set up all my spraying masks and applied enough green so the strips underneath almost disappear. Hindsight I should have made the paint thick enough so the strips -just- disappear but it's OK anyway.
Here's how much green I applied: starting and finish:
density.jpg

I put a blower on the paint and let it sit for about 6hrs to dry.

Then I made a big blunder.

I went to apply the stencil using Titanium white but the color bled through to the glass. I had no other option but to scrape that entire side off and apply the green again.
I let it dry on a blower for a few hours. I needed to prevent the bleed through so I applied a couple thin coats of Tripple Thick to the green and let it set overnight.

I tried spraying the stencil again. You can see I hold down the stencil edges with what ever is at hand:
spraying.jpg

I had fairly good success:
rear.jpg

I wish I would have built up the green a bit thicker. But this will do:
front.jpg

I am letting this dry for a while then put the glass in the game and check alignment of the stencilled paint. I will need to build up several more layers of the green around the stencilled paint before applying the final black mask.

Thanks, I'll take that as a big compliment.
This is more of a challenge than anything else. I'll probably go with a reproduction once my pinball budget is replenished. I calculate in about 20 years.
Ha ha ha

Been busy.
Everything aligned well with the light box.
I needed to finish the match numbers because they lit up circles around the numbers through the thin green paint, and I just want the numbers to light. I couldn't just apply black masking because the green paint was too thin and it would make it abnormally dark. So I had to build up the thickness of the green.
I used my round steel washers to cover up the match numbers and TILT, and masked over the ball rack translucents. Then sprayed several layers of the same color green. Then followed by several layers of pure black masking.

Once dry I removed all the steel circles and other masking and brush-applied green around the numbers. When dry, I followed by a layer of light blocking black.
Here you see one side is done:
masking match.jpg

I let that dry, then put a light much brighter than any #44 lamp on the front side of the glass to expose the brush strokes in the black light masking layer. Using the bleeding light as a guide, I brushed a second coat of black to finish it. See here that half are done:
masking match 2.jpg
Here are the match numbers and Tilt and the rack all done, front lit:
FrontLit.jpg
And back lit:
BackLit.jpg

The blue billard table looked pretty bad. The light blotchy parts were actually where the paint had removed from the glass, held in place by TrippleThick. There isn't any light features there so I scraped that clean:
Scraped.jpg
I mixed some blue paint, did some masking and airbrushed:
Done.jpg
The black border lines are a bit jagged but I am happy with this.

Another thing to note:
With the glass front-lit it is easy to see cracks around the translucent parts:
cracks.jpg
These hair-line cracks look terrible on the game so I dab some black light masking paint.

Actually, I don't intend this to be a tutorial but rather a journey through mistakes and corrections. If I were -really- good at this then I'd make it as a tutorial, but as we see this is trial and error.

I tried to fix the dreaded face tonight. This area is masked so using a regular brush is perfectly fine.

Here is the original. I see part of her chin had broken loose and floated in the Tripplethick and became frozen just under the nose:
1-original.jpg

Here I have scraped it away but careful to preserve 3 reference points: The top of the nose, bottom of the chin and the end of her mouth. The jagged edge in the white is the edge of the scraped tripple thick. Hopefully it won't be a problem later:
2-scraped.jpg

Then I used the photo newmantjn (Post #11) provided to create a sketch. I actually used the pinch-zoom in my phone for a correct size, then put a paper on top of my phone and traced it directly:
3-drawing.jpg

I held the paper on the paint side to check alignment and make adjustments to the sketch:
4-alignment chk.jpg

Since I will be painting on the opposite side of the glass, I will need to see the other side of the sketch. So I put the sketch on a back lit glass and traced it to the other side of the paper. Then I aligned the sketch and taped it onto the glass:
5-posisioned.jpg

The first layer of paint is almost always going to be the black borders. I've applied the border with a fine tip brush and check it, keeping in mind parallax and the glass.
Ehh, could be better but good enough for this project.
6-blk.jpg

The original had some orange under the chin, lips and dimple so that is the next layer:
7-or.jpg

Finally, I mixed paint for the skin. Light brown, a bit of mustard yellow and a speck of dark brown. I let that dry then a dab of Titanium white for the teeth and a thicker build-up of the flesh tone. The teeth turned out kinda funky but this is good enough for this project. The background is the blue padding I am using on my table:
8-skin.jpg

Yes absolutely!
I think all the faces on the game is butt-ass ugly(can I say butt-ass ugly?). Only possible exception is the bottom right brunette. Even then, ehh. The female artwork on this pin was disappointing even back in the 70's when I had the game in our basement.

It's a good game, even better if Art Senholm would have done the graphics a bit differently regarding the characters. Lord knows he had the talent.

Now that the ladies face is repaired, I began to tackle the dreaded blue curtain hole tonight.

The light blue vertical folds should be the first layer, not the dark curtain.
So I mixed some light blue and white until a fairly good match. I laid a strip of tape on the glass to correspond with the existing fold artwork... so I would have a reference where to paint the backside. I laid a single vertical stripe with a brush then used a large hobby pin to dab the jagged edges:
Rear Stripes.jpg

You'll be able to tell it's touched up but might look alright:
Front Stripes.jpg

I had a lot of that color paint mixed up, and used the rest of it to fill in the cracks that look so ugly when back lit. The color corresponds to the artwork on the front:
Back lit Cracks.jpg

There were actually a lot of cracks found with the light in the rear, and I used up all my mixed color paint:
Cracks.jpg

I'll let this sit over night then mask off the Target Pool Logo and shoot some dark blue and hopefully the curtains will look OK.

Alright, this BG project has come to an end.

I didn't want to bore anyone following this thread with the same old processes rehashed over and over. Since the last post I've:

*Mixed the dark blue curtain color and sprayed.
*Scraped the light blue "walls" on the left & right sides (Cracked, chipped). Mixed colors and sprayed.
*Made a positional template of score reel window positions, then scraped away the paint- and respray.
*TrippleThicked the new score reel glass frosting so cleaning the windows won't remove the white acrylic paint.
*Spot-touched up the 3 illuminated characters around the pool table.
*Painted a mask around the Target Pool logo.
*Sprayed a light layer of orange paint to improve the logo, over the existing orange.
*Sprayed a light layer of pure white over all illuminated areas. This ensures the glass will visibly glow more than the lights illuminating them.
*Sprayed the entire rear of the glass a thicker layer of pure white. That is to help the reflectivity of light.

This is obviously not reproduction quality. It could be a lot better if I were willing to spend more time and a better artist.
Lots to be critical about but it is vastly better than before in my opinion and that was my goal.
In that, I think the project was a good success.

Final pics. I tried to eliminate glass reflections much as possible:
Rear.jpg
Front.jpg
Front Mach.jpg
lit.jpg

This is the most dramatic and noticeable improvement:
Score.jpg

Now this PIA is finally finished I can get back to completing my TP project. It needs to be DONE.