I frosted the cake with SMBC, I was thinking of using an ivory colored royal icing to make the Faux lid. Any suggestions, it's due today?!
THANKS!!!!

Yeah, if the box is closed, and you're just showing the box lid like a closed shoe box, just get a real wide real big rose tip and pipe the lid effect around the top ledge with the smbc.

yeah or even the icer tip, then it goes on evenly and straight, and "grabs" on with the zigzaggy grabby side (yes, that is technical lingo ladies) then you can go over very carefully with a small sngled spatula around the bottom edge of the lid to touch up/blend in any of the jagged (ok but really..what would/do you call that? the toothed edge? i should just stop trying here) edge that might be bulging or showing a bit from the icer tip. i always liked this a bit better than the rose tip, as then you get a more defined box lid, and the icing is coming out in an even line as opposed to the lrg rose tips and their tapered-ness. (<-- more technical lingo)

Yeah for sure what she said ^^^ good call. Icer tip or large basket weave tip. Or it you don't have a icer tip you could hack up a rose tip. Smoosh open the skinny end so both ends open about the same amount.

But I would not use royal because it will contrast too much. You want it to all look the same.

Or or or just lay a little piece of fondant on top that overlaps--but it's gotta be a square cake--give us some more information because I have a day off and my thyroid says, "do absolutely nothing" and I'm like "ok ok don't be so pushy already."

OK, I had to leave the house before the replies rolled in so here's what I did>>
I made a small lid of fondant anyway (no charge to bride) the cake called for royal icing embellishment on the lid which was also brushed with super pearl. It turned out great, the Bride hugged me so hard it hurt (in a good way) Thanks for all the suggestions, I LOVE this place!!!!