Some of these tips may sound like common sense, but...
“Top 10” Things NOT to do to a pinball back glass:
1 ) Don’t store back glasses in areas of extreme temperature changes (hot/cold) or keep them in areas such as vehicles, garages where they are exposed to rapid changes (even overnight). If you do, you may find a surprise waiting for you the next day. If your games are stored in a non climate control garage, be mindful of the temperature range that exists. Does the winter cause the temperature to drop lower than 30 F? What are the humidity conditions? What is the highest temperature that is normally existing in the summer? Is it higher than 80 F? Is there proper water drainage in the garage? Block and black out all windows in a garage. These are the primary source of temperature changes outside of weather and allow for fading of colors. Seal doorways to prevent moisture from entering and use barrier materials to prevent moisture from reaching cabinets of machines as well. One single year can do more damage than people ever realize. If you have games upright without legs on, make sure you use pallets. Never leaves on the floor for long periods of time, as both moisture and temperature will cause problems.
2 ) Don’t “free hand” back glasses (one hand) when removing them or moving them out of games, and always use the two way "offhand" hold, preferably top and bottom, not side to side to avoid "flexing"
3 ) Don’t put back glasses in direct sunlight (meaning don’t put the games next to windows) as the inking will fade over time
4 ) Don’t use varathane, urethanes, lacquers, or clear coat paints or finishes on back glasses, they will melt and destroy the ink, or at best case shorten the lifespan of the ink layers due to different expansion rates or yellow the paint. You should not "clear coat" back glasses. If you see an old can of "Save Your Glass" throw the product away, it is destructive! Additionally, do not spray glass cleaners, deodorizers, or other products on the backside of the backglass with the ink screening, it will damage the paint! It is dangerous to "clean" dirt off a backglass in any shape or form. Even translites can be damaged this way, if not careful.
5 ) Don’t install back glasses in games without protective edge trimming on all sides AND a lift channel, or you risk chipping or breaking them
6 ) Don’t “force” a back glass into a back box, something is WRONG (did you forget to undo the lock?)
7) Don’t do full coating of back glasses with Triple Thick Crystal Clear Glaze or water based acrylic clear, if the game remains in proper environmental conditions, you are not putting back glasses in long term storage, or they are not delaminating, it is not necessary. Do not use the recently popular "saran wrap + KTTCCC" method, it does NOT work, makes a mess, and makes the glass UNREPAIRABLE for future use. Do not use any type of tape for "masking", as you WILL LIFT PAINT.
8 ) Don’t use mylar unless you really have to and if you must do so in small spots, as it may never be able to be removed without lifting the inking and it makes future restorations difficult.
9 ) Don’t put back glasses down on hard surfaces such as floors EVER, and NEVER lay them flat, always store them upright
10 ) Don't attempt to peel, "pop", or re glue a veining, cracking, or flaking back glass, seal the damage before it spreads by spraying the glass with TT or brush on acrylic sealer.
FINAL BONUS POINTS: Don’t use incorrect rated bulbs in back box light panels that produce excess heat (LEDS can be a superb alternative if used tastefully), in order to prevent discoloration and damage. Remove all #44 and replace with #47 at minimum if these are used. Excessive bulbs in certain games can be just removed all together, by using half the number in the light panel and generate the same effect.
Lately, I have seen more crazy things than usual.
Keep those backglasses safe!
This is a pinball "public service announcement".
Feel free to provide additions.