[Questions] Shadowless booster pack from a blister. Seller could know that inside are unlimited instead of shadowless?

Hello poke fans,

Recently I bought a base set shadowless booster pack from a seller on ebay. It's a short crimp, I read everywhere that you have 50/50 chance but it is that really true? It is possible that the seller could know if inside there are unlimited cards even from a blister pack? I even read about the wizard logo on the back of the booster, if it is blue it's shadowless, if it is purple are unlimited. It is true?

Thank you everyone, it's really hard to find any information about this

You will never get a guaranteed 100% legit box on Amazon, EBay, or any other third-party sellers. You just don't know if the packs are weighed, or other highly nuanced andfrankly mythical nonsense people have conjured to "I swear it's real bro!".

I don't know if you box it legit, and neither will you until you open it. I wish you luck though.

No it's not a box but a booster pack. It is weighed and it's heavy, I know the pack hasn't been resealed. The problem is, how to really know If inside are unlimited or shadowless? Aren't there other certified method? Except of course for the tradable game card in the end. Maybe the artwork color could tell something?

Only way to know for sure is to open it.

I dealt with a lot of shadowless packs back in the day. I had two full boxes come to me that were shadowless. The packs were significantly longer than my other packs and, if memory serves me, the printing on the wrapper was not as clear.
I thought I still had one of these packs but I can't find it.