Weird stain on backside of blotter

I just grabbed a batch of tabs which feature super mario characters. These are the pics

This is the front side:http://imgur.com/M5mBZ.jpg

This is the backside: (notice the bumpy stainy part)
http://imgur.com/XevSo.jpg

Any ideas? Im sure it isnt anything to worry about since I have grabbed before the same stuff and it was fine. Has anyone come across this before or know what it can be?

 

the papers layers bloated while being soaked, they dried and bubbled .. Imo. I cant not tell you for real cause im not the one holding it..

 

i dunno mang its definetly gonna kill you

 

Is it a stain or is it something you can scrape off? Looks like mold I dunno

 

Never seen that before. Huh. I would want to play it safe for sure. However, you said you have had the same batch?

 

You shouldn't have paid for that without being told what it was, and then you still shouldn't have paid for it. I hope you got it for free.

 

Yes I have seen something similar before, in this thread about using RC's to make blotter hits. Sure you're getting LSD?

http://www.hipforums.com/newforums/showthread.php?t=410143&f=126

 

ah.. yes you can see them being very similar. weird cause Ive seen some blot like this many yrs ago. Ill add that is was not as raised up or bubbled like that. but it was bubbled..
these pic on this link do look alot more like what you have.

 

Interesting, i dosed on blotters from that same piece that did not have the weird bubbles on the back and i am definitely sure that it was acid. Have not tried the one with the bubbles yet, but if it was attached to the same sheet is there a chance that some of the sheet was dosed with another substance?

 

well there is a chance, but i think it is very unlikely.

 

looks like it can be scraped off. can it?