I think its a combination of changes rather than one thing. But ultimately the critical problem isn't wood or clear or chemicals - its the lack of maturity in this industry.
Some changes are related to cost, some related to regulations. What's clear (hoho) is that if the pinball companies would invest in more R&D and working out a proper solution or aligning as an industry on what is acceptable or not; it would save them money and drive more customer satisfaction across the market - pinball is too busy fighting for market share in a tiny market rather than figuring out how they collectively grow the market. I despair of the short sightedness of the pinball industries' attitude on this, which appears to be focused on who's fault is it in the supply chain rather than getting the supply chain together to fix it, so Stern working with JJP and Spooky and CGC and AP and all of their suppliers. It helps none of them that this problem exists. Pinball companies could agree to a set of playfield standards, then use those to build games, I think most people would pay $50 more to know they get a playfield with no issues. I certainly would.
An issue like this in any other manufacturing area would drive immediate response, if my industry behaved like this we'd be out of business or hauled in front of the government and told to fix it. Since I got back into pinball 4 years ago its been a constant drag on all of our enjoyment and if I may be so bold, I plead to all the pinball manufacturers - what you are doing isn't working for us, please work together to resolve this for the good of the industry.
Neil.