how do I make large letters for a cork trivet I'm trying to make.....

[a kennedy]

Here are the letters:

R S

I've got them at max font size which is 288 but they're still not large enough to use, I need them bigger. I'm trying to cut out these letters and use them as a template for trivets for an 5th (wooden) anniversary. They drink wine, and I thought cork would be close to wood and thought making trivets with their initials would be kinda neat. Just can't get the letters big enough to cut our for the template. The font I'm using is, Princetown LET, but can't show the style here for some reason, don't know how to cut and past them here. Any suggestions? Thanks.