This is a large envelope made out of poster board. I made this because I don’t have the prettiest fireplace and wanted to cover it up to match my Valentine’s Day theme. It would be a great project for anyone who wants a large Valentine’s Day prop.
Step 11. Before you get started, you're going to want to measure your fireplace opening. This will determine how big you need to make you envelope. My fireplace measured just a bit over 36in x 31in.2. Now that you've measured your fireplace, take your tri-fold poster board and cut the flaps off. To do this, take your ruler and place it along the crease of the flap fold and use this as a guide. Cut right along this fold. You should end up with three pieces.
Step 2Here is where you'll need to know the height of your fireplace. You're going to overlap and glue the smaller board piece on top of the larger board piece. Combine the two pieces so that it is at least one to two inches larger than the height of your fireplace. You'll need the extra portion to secure the envelope to your fireplace.
Step 3Take the last piece of board and mark the center on one of the long edges. Since the poster board is 36in in height, mark at 17.5in on one edge. This is where the point of the envelope will be. Take your ruler and make a triangle out of the last poster board. Don't glue this on yet.
Step 4It should look like this.
Step 5Take the duck tape and start trimming the bottom edge of envelope tip. I made my tape edge about 5/16" wide.
Step 6Trim the bottom portion of the envelope before you glue down the envelope tip. I glued the tip down and then realized that I had to nudge the tape under the flap...do the bottom first. When the bottom is done, glue down the envelope tip and trim the top portion of the envelope.
Step 7Since the envelope flap is made out of two boards, you'll want to cover the area where they butt next to each other. I chose to use the duck tape to make three decorative lines across the envelope flap. The center line is covering the area where the boards meet. I also made one line across the bottom of my envelope. This is where I ran out of duck tape :-(
Step 8I finished the envelope with a large felt heart, but you can decorate it however you want. Doilies would be nice too. Use your imagination. To secure the envelope to the fireplace, I used double sided 3M tape along the back top edge of the envelope (this is why you needed the extra length for the height).