actually there is a cheaper, and maybe better alternative than the ikea mat. Art Friend sells this translucent plastic sheets in A3 size, think only bout $2 per sheet? They have white, as well as other colours. Maybe can get a few colours and add some artistic touch to your shots? haha... Well, since they're so cheap anyway. They're slightly thinner than a credit card, but very flexible, kinda like those file folders, can cut to size and glue it up, will look more presentable than the ikea mat, which somehow reminds me of an octopus. not sure about the effect though, haven't got a flash unit myself to try out.