I have two silicone ateco mats, different sizes, that have performed very differently for me.
The first is a square blue one, with concentric white circles on it ... I think it's 20x20 inches, so not very large, but extremely convenient due mainly to the fact that I use cornstarch or powdered sugar to dust it, and nothing ever sticks. Beautiful!!!
The second is a much larger mat, 40 inches long, that is tan (looks like it has a woven pattern on it, but fondant rolls out smooth) with blue borders, and inches marked out. Fantastic size for larger cakes, but if I try to roll ANYTHING on it with cornstarch or powdered sugar, it sticks. Always. No matter what I do to the stupid fondant (and I always use my same recipe, and can work on it on any other surface with no problem), it will stick with dusting. If I use a light coat of shortening, it comes off of the mat beautifully and I can work with it well. Problem is, I hate using the shortening. I love how my hands slide across the surface of the cake with dusting, and I just can't do the same with shortening.

So ... any ideas as to why the two silicone mats from the same company work so differently? And more importantly, any ideas as to how I could use the large mat with PS instead of shortening and make it work? (I don't want to go out and buy a roll of vinyl or anything, I just want to use what tools I already have :/) ... it works fine, but I wish it could work better!

Thanks!

Interesting that two mats from the same company would be so different. Obviously they used different materials. Are you sure both mats are intended for the same use?

its because the small mat and the large mat are the same brand, not from the same manufacturer i have the exact same mat, but i purchased it with a red grid and fat daddio's tm on it:

http://www.thebakerskitchen.net/Fat-Daddios-Silicone-Fondant-Mat-24-x-36.aspx

you have the same mat by ateco:

https://www.atecousa.net/Merchant2/merchant.mvc?Screen=PROD&Category_Code=fondt&Product_Code=698

and you can tell that they are exactly the same except the color and brand tm. i love my mat though, its weird that you say that because all i use is corn starch/ps and i never have any problems. the only time its stuck is when the fondant itself was too sticky, but you mentioned its not a problem with the fondant.

sorry i can't be of more help, i just made that realization a few months ago (that the mats were the same) and thought i'd shed some light as to why its different than your smaller mat

Coral3, yes, they are technically intended for the same thing. Cakearchitect, how interesting that you only use cornstarch! I guess that's encouraging in a way ... I can't fathom why it wouldn't work, and then work perfectly on another mat, but you're right, that's exactly the large mat that I have (I overshot when I said 40inches, I guess! ).

Thanks for your feedback! Love this sort of "what works for me" line of answers ...