Wow, great stuff. I pick up errors, promos, and other pre-production stuff as part of my interest in oddball cards in general. I have an oddball W3 from the 3-card "wood" chase set from the "Hershey's Trading Cards: The Collector's Series" (Dart Flipcards, 1995) that was offered on Ebay a couple of years ago. It's the card with an outlined blank space where artwork from an old Hershey's ad was going to be applied later. Most people want to know why I would pay anything for that, but yeah, it's an otherwise unseen peek into the card-making process.

Wolverine 651,

In reference to your mention of color variations among copies of the same single on Blowout (why they happen), I'm pretty sure it's the result of a particular color running out on the printer with a default to another shade of that color. I'd seen cards like that before but didn't make that connection until printing a photo in which what was supposed to be green grass came out as a blue-green instead. Back in the late 90's, I used to buy a good number of Tomorrowland (1997) promos from a dealer who specialized in Disneyland giveaways/exclusives. Here's a pair of Tomorrowland promos that shows the color variation (lighter blue background in part and purple background in the lower right corner) next to the the more uniform blue color that the cards almost always show. I've seen a couple of other similar examples offered on Ebay since then.

I’ve seen a lot of Star Wars finest refractor cards with no gold on the back. Obviously they ran out of gold ink. Back then I was wondering if I should try a set of no gold cards, but decided not to. I didn’t know how many uncut sheets were missing the gold ink, so I didn’t bother collecting them.

David