FYI: you can order mousepads at walmart.com. upload your image (family friendly) and send it off. it is standard mousepad size ~7x9?. im sure someone could create a template for this (include blackout spots for timer placement/ possibly different color dots on blackout for where to cut out holes) and just drop your CUSTOM design on the template, upload to walmart.com, have your mat shipped to your house in a few days. I believe the pricetag is $8USD ish?
for chris, i also would like to have a mat that is slightly larger than minimat. I like the width of the original stackmat. i think a buffer of 1-2 inch shorter on the width is fine. i do not like the length of the orginal. it is MUCH too long. its not like we're stacking cups or anything stupid like that. i will pretty much +1 anything that is slightly wider than the timer, but not shorter. i am also concerned with the thickness. i have tried mousepads (1/16, 1/8, 1/4 of rubber) and 1/4 inch is much to thick to fit the timer (the magnet keeping the timer stable). however, i would feel a lot better about slamming down a larger puzzle on something more padded. so finding a good compromise would be nice. i think it would be nice if you were to order a sample packet from custommousepads.com to get a good feel of whats going on with them. if we go with the mousepad, i think these would probably be a good way to go; competitive price, many different options, and seems like they have experience in doing these kind of projects. just browsing their website and reading review, i get the feeling that this type of project would be very easy for them and would come out high quality.
lastly for design. I WOULD NOT BUY ANYTHING THAT WAS OVERLY COMPLEX! anything with zoom fading or optical illusions, these things i do not want to see as im solving a colored cube. this would be EXTREMELY distracting if you were solving and caught a glance, such as a quick look at the timer. not to mention the optical illusion in general. maybe a cool artwork on the wall, not something i want to have anywhere near my general direction of sight while im trying to do something that is very sight intensive. i would be fine with solid color with a little jazz, much like stackmat's original solid color designs. also, anything cubing related would be cool, but i would not want to over do it because it would become a distraction. uncluttered, simple, but not boring. if i think of a design, i will try to post it.
thank you for trying to do this for the community. i will probably support you regardless of design or size, but i wanted to give my advice^^;