The pack on the left I purchased from the store over 16 years ago, the one on the right I just purchased.
Is one rarer than the other?? My main concerns are on the front: the smaller TRADING CARD GAME box with offset printing, oversaturated/bright colors, and the “tm” next to pokemon.
The one on the left has a curved wizards logo and 1999-2000 under the flap, while the one on the right has a square Wizards logo, and only says 1999 under the flap.
Thanks!
I don’t know much about US packs, so I can’t weigh in on why the two packs are different. However, I did notice something else. The trademark designation (™) on the left pack is printed in black, while the on on the right pack is printed in white.
EDIT: Looking even more closely, I see that the font for the “11 ADDITIONAL GAME CARDS” is different between the two. It’s a subtle difference, with the “G” in “GAME” and the “C” in “CARDS” being the most noticeable.
The pack on the left (made in U.S.A, 1999-2000 copywrite) is a much tougher variant to find. They come from Blue Wing booster boxes with the US, CAN, Asia & Latin America distributor info only (single calling code). It only contains the 1999-2000 copywrite non-holos (no holos). The one on the right is the most common variant 
The pack on the right is your “normal” Unlimited Base Set Pack. The pack on the left sounds like it could be a “U.K.” (1999-2000) Base Set Pack.
In regards to the pack on the left; what does the back flap look like? Is it just the normal “dotted” pattern, or does it have vertical lines? If it does have the vertical lines, that’s the U.K. Version.
Just normal dotted I think but the overall pack looks so different from any pack I see online.
@pokenoob feel free to read this article I wrote about Base booster boxes & packs. I believe every base booster pack variant discovered so far is included. Its a work in progress so new will be added as time goes on.
www.elitefourum.com/t/identifying-shadowless-unlimited-base-set-boxes-packs/16993/1
Hey thanks! Looks to be that the packs are #9. Are they rather than others? These were the packs I would consistently buy from the store as a kid.