Photo Calendar with Riddles - how to hide the answers?

[TheKitchenWitch]

Every year I do a photo calendar for DH for work, with photos of the kids and pets on it. The kids help with little illustrations and writing the months in fancy writing etc so it's not just pics. And every now and again we throw in something extra, like we a Dad Jokes one, and a Quotes one etc.

This year I'm putting riddles in it, but I'm a bit stuck as to how to add the solutions? Shall I stick it on the back of each month, under a flap to lift up? Or....well that's the thing, I can't think how else to do it!
Any other fabulous ideas?

That's a lovely present. I think I would have a separate envelope stuck on the back of the calendar, write the answers on slips of paper which are then folded over and sealed in some way (wax would be ideal but tape would work) with the month on the outside.

Oh that's a good idea!