1966 Topps Card Stock
 

I'm certain this has been covered elsewhere (though a search only found a thread related to the 1966 football set), but I was wondering if someone could just sum up the thinking on the reasons for the card stock differences in the 1966 baseball set - did Topps simply run out of one? I just finished putting a set together and I noticed the white stock seems to be rarer, and that it seems to be most prevalent in the 1st and 7th series - anything to that?

The fact that my Ranew, Groat, Uecker and Johnson "no trade" variations are all on the lighter stock makes me think that's what they started with.

Or, is there a more interesting story in there someplace?

The story is probably very boring; we can't know the exacts of why but it is probable that they just ran out of one type that day or the other type was in easier reach. It wasn't like anybody cared at the time.

Scarcity between the two stocks, and the two stocks themselves, change between series. The lighter stock can get really tough in some of the middle series. Some series may have 3 stocks. Series 6 is the easy one to spot the differences, as it is a bright white and a cream and not a pedantic difference. I collect series 6 both ways as a result, the others are rather difficult to collect buying online as it's hard to ID them correctly from scans in many cases.