Just stopped in to see if you have got ten a solution to your dilemma. Lol!.
Depends on how large you want it. I don't have one larg enough that you can cut a dress pattern on, however, I've seen them that large at the sewing machine store I go too, so they do exist. You could check architect supply place for a really large one. Or places that do framing for art as they have to cut mats.
Also, no matter how you join them, there would be a little valley where they are joined. This would disrupt the accurarcy of your cutting, albeit a tiny amount.
Are you near an Ikea store?
What about a desk mat?
I got one from Ikea a while ago and use it as a pastry mat
Couldn't see one just now on line but there is a floor one clear 120 x 100 worth a look to see if you could work with this?
Even Bunnings sometimes has something you never thought of.
Thank you .No Ikea but Bunnings is in the same centre as Spotlight & my husband has been trying to get me to go to Spotlight so he can go to Bunnings but have too many things to do this week.
Duck tape? Just kidding though husband says it fixes anything! Hugs. Nan
No idea at all but you can buy very large cutting mats
I have 2 42cm x57 cm which are usually large enough.
I have been having some hand problems & I have been using a rotary cutter but the mats are not large enough to cut out dress patterns on.
I have seen those large mats but storing one ,so it doesn't get bent out of shape would be a problem.