On the baseball front, Topp first inserted posters into the regular Baseball packs in 1967 with a set of 32 appearing in two series of 16. These were much smaller than the posters that would follow and I only mention them here as a point of reference for in 1968 Topps followed with a standalone issue of 24 oversized posters:
As you can see, these were quite large at 9 3/4" x 18 1/8" (approximately as I find these have shrunk a little after almost 50 years in the wild). The posters are printed on paper similar to that of the 1967 inserts, a very cheap stock that will likely disintegrate another 50 years from now. The flimsiness of the stock causes these to separate at the horizontal folds and they must be handled with care. There is not a whole lot to like about them actually, other than the poses.
They came in this pack:
It's a little obscured but the product code ends in an 8, clearly marking these as a 1968 issue. You can see one poster and a stick of gum were offered for a nickel. No big deal except two years later we are confronted with this:
That is a 1970 product code and the design essentially is the same as in 1968. We do have a price increase to a dime and a move to Duryea noted on the wrapper (both in line with how Topps was doing things at the time) and now multiple posters are included in the pack (two I believe). These are the same posters as in 1968 and clearly the full run of 24 was included, which is odd because two major subjects had retired in the interim (Mantle and Drysdale) and numerous players had changed teams. In addition, it is quite strange Topps reissued a baseball set two years after the fact with gum as their previous pattern was to make any such reissues non-confectionery in nature so as not to run afoul of their various contracts. Perhaps their deal with the MLBPA in 1968 gave them the right to do this. It's worth noting some but not all team logos on these posters are obscured. The whole setup is strange and I wonder what markets these actually appeared in.
In between all this, as I want to be thorough, Topps offered a team poster issue in 1969 that was a little bit larger than the 68's and printed on much better stock. I've already discussed those here so no need to repeat myself. An insert similar to the 67's also came in the 1970 Baseball packs and featured a better design and somewhat upgraded stock when compared to the 1967 issue. Again, this set, which was 24 in number, is not the focal point here and only a point of reference.
Amazingly, no baseball poster set was issued in 1971.
Topps saved their best for last and in 1972 offered a gorgeous 24 subject, borderless poster set printed on thick stock:
Pictures don't do these justice, the colors are extremely vivid. These are roughly the same size as the 1968's but they hold up much better. They used to be much harder to find as the 72's look to have been a somewhat limited release. What's happening lately though is that the 68's are commanding higher prices, perhaps because so many are deteriorating and the survival rate for the 72's would seem to be much higher, or maybe there was a find of the latter issue.
The packs are like so:
Once again, it looks like two posters and gum came inside. Like all of the short Topps baseball specials, the set is loaded with Hall of Famers.
I'll leave off with some poster porn. In the first, you can really see the difference in paper stock between 1968 and 1972, while the bottom scan is just kind of neat. You also get a Mantle collectible with the 1968 box (no offense Joe) so I wonder who graced the box of the 1970 reissue?