Need help mounting quilt blocks
 

I will be entering 2 quilt blocks in our local fair. The category says: "Quilt blocks, 2 different, Un-quilted and displayed on card stock or Bristol board"
Elsewhere it says that pins other than safety pins are not allowed.
How will I mount these blocks to the cardstock? Sew them to the cardstock? Glue?
This is my first time entering this category, and I really need suggestions.

I don't know how to mount them, but the bristol board can be gotten at Jo-Ann's in their frame dept or Hobby Lobby.

That's exactly what I was doing tonight ... I use foam core, and use push pins to hold the blocks in place. And yes, out fairs say you must use safety pins only. However, there's never been a problem. I like the foam core, as when they display the block, it keeps it all sitting nice and perky, whereas bristol board can flop so easy.

Tartan has a good suggestion ... however, when Judging I would suspect they will want to look at the back. Having them stitched in place would not be conducive for that. At least that has been my experience when showing blocks.

You can buy mounting board at most craft places that have a picture framing area. It is foam core that has sticky on the front. I've framed cross-stitch work with it. It can either be stiff foam core or padded.

You could use sticky Velcro or double sided tape just at the top and let the rest hang.

Spray basting?

When I mounted counted cross stitch I used masking tape at the top to hold it still initially, then did the criss cross "lacing" with thread to get it to fit snugly from side to side. Then removed the tape and repeated the "lacing" to get the top and bottom snug as well. Since my margin was only a couple inches all the way around (plus the half inch turned under to prevent raveling while stitching) there was quite a bit of thread used in the criss crossing. I don't recall what I mounted it on - maybe coroplast like used for sign making or mat board. Something that wouldn't bend from the stretching of the fabric over it.