Forum:Differences between regions?

Hi,

I was wondering if there is a possibility of there being slight differences between cards from different regions. I ask this as I bought a booster box from Canada and to complete the set I have been buying cards from the UK through ebay. Two single cards I bought from ebay (Both from the same seller) are both slightly darker in colour (The orange and green backgrounds of the cards), the cards feel ever so slightly thicker, seem to have a slight gloss to them and most worryingly of all the holographic can been seen in certain light underneath the text and green background (Skyscraper from Cybernetic Revolution). Could this be because these two have been out of the packs longer than the rest also?

Thanks.