When you've got it rolled up suck a good few lungfulls of the remaining air out of it and it will slip in the stuffscac a treat.
A technique learned from URW (I think) is to roll the mat to the end with the valve opened. Close the valve and unroll. Roll again, keeping the valve closed until you near the end then open, finish rolling and close the valve. Goes in the stuffsac with room to spare.
Phil's method certainly sounds less involved so I'll give it a go. Cheers, Thomas.
