When I made yesterday’s card, I masked off the center panel with blue painter’s tape. The challenge is to get a tight “seal” at the edge of tape so that ink doesn’t seep underneath without adhering the tape so securely that it rips your finished panel when you remove it. My solution is to cut a length of tape, then press it against my jeans or sweats several times. This removes some of the tack from the tape; it still provides a barrier to the ink, but shouldn’t tear the paper when removed. And when removing the tape, don’t lift it up, pull it back on itself slowly.
For another masked-panel card, check out my Spring Trees card.