I wanted to make some backpack straps that actually feel like backpack straps...so I got creative.
The DIY sites often suggest putting some interfacing into backpack straps, but they just don't feel right. Too flimsy. As I made my nephew a backpack for Christmas this year, I found myself trying to figure out how to make backpack straps that really feel like backpack straps.
I found some sites for backpackers and I learned that backpack straps typically use a foam called EVA foam. However, everything I found was something I'd have to order and wait for, and waiting is not always my method. Turns out that some of those padded floor tiles that fit together like a jigsaw puzzle are made of EVA foam. And, they were available at my local Home Depot.
So, I went to Home Depot and looked at what they had in stock, and the best deal was a 4-pack of these tiles that was firm enough to feel substantial, yet flexible and cushy enough to work as an insert on straps.
Here's how I did it:
I made sleeves for the straps by cutting four pieces of my fabric (2 for each strap) about 17.5" x 3.5". I wanted them to be tapered at one end, because that's where I would slide in some nylon webbing to hold the ladder lock, so that would be the bottom of the strap. To taper it, I made a mark at the center of the short side and centered the nylon webbing over that mark to mark the edges of the webbing. I think the webbing I used was 1.25" wide.
Then, I made marks at 1/2" up from those marks on the short end to account for a seam allowance (which I would be folding under to create a hem after inserting the nylon webbing).
Next, I made marks at about 2" up from the bottom and 1/2" in (to account for seam allowance) and drew a line on either side to connect the dots to create my tapered line.
I sewed down both long ends (leaving the top and bottom open), following a 1/2" seam allowance and then following the tapered lines. I stopped at 1/2" from the bottom. and serged it within the seam allowance.
I turned the sleeve right side out and pressed it. Then, I cut down two pieces of the flooring mat (foam). I don't know the exact measurements because I just eyeballed it. I made sure it was shorter than the sleeve because I wanted the very top to be clear of the foam (there was no way I was going to be sewing through the foam) so that I could attach the straps to the bag.
To cut the foam, I used my rotary cutter to score a line and then made several passes to get through all the foam.
Then, I slid the foam into the sleeve, getting it down to the taper point.
I took the piece of nylon webbing and fed it around the upper loop of the ladder lock and made sure I had the right side of the lock up. I inserted that into the tapered end of the strap sleeve and turned the fabric edges to the inside to create a hem.
Finally, I used a tight zigzag stitch to close the bottom, through the nylon webbing. I did another row of zigzag and then finished it off with a straight stitch as close as I could get to the bottom of the foam to hold everything in place.