The 24x36" Olfa is on sale at JoAnn's online for $35.99, and there's a free shipping code. They're on sale at 40% to 50% off in the stores frequently, and Olfa has a great reputation. I haven't heard of the Alvin brand, but it looks interesting. The write-up says that it's 3mm thick, while the Olfa is only 1.5mm. (I'm not sure whether that's a good thing, but it probably means the Alvin would keep its shape better if stored in adverse conditions.) If you get it, let us know how you like it. I also wonder if the black/white markings might be easier to see than the yellow/green on the Olfa.