We don't charge for full bleed (edge to edge) and our standard coro is 4mm white. Given the right conditions (sun beaming against
sign back) you can see some show through on some jobs depending on coverage, especially if there is a lot of white negative space. If you are truly concerned, just let your trade printer know you would like your job run on opaque. We offer this option, it's basically $6 more per 4 x 8 sheet or $.60/
sign. On long runs it's even less.