My mattress is made from foam, but I suppose similarly and with a little imagination you could modify a mattress that is made from other material too.
I chose a half round shape because that fit my living room/bedroom best but as you'll see you can do any shape you like, the sky's the limit!! :)
Step 1: Materials and Tools.
- a foam mattress
- sewing thread to match the colour of the mattress
- lifting pallets for the bed to stand on (optional)
- scissors or small sharp knife
- big sharp knife
- (optional) knife sharpener (if your knife isn't sharp enough)
- sewing needle
- (optional) jigsaw (to modify the pallets)
- (optional) hammer, screwdriver or drill and wood screws (to modify the pallets)
- (optional) laptop or/and other entertainment (to keep you from getting incredibly bored through the sewing procedure)
Step 2: Preparing the Matress
Using the scissors or small sharp knife remove carefully the thread that is connecting the small cotton stripe with the top and the middle part of the cover. Repeat for the thin cotton stripe that connects the middle and bottom parts of the cover. You only need to remove this at the place of the mattress you're going to modify.
Pull the fabrics away from the area you want to modify.
Step 3: Shaping the Mattress (and Optionally the Pallets)
Sharpen your knife if necessary and carefully cut the mattress at the desired shape. If the knife is sharp enough, a foam mattress should be cut like butter!
(Optional: lifting pallets:
Using the marker draw the new shape of the mattress on the pallets. Using the jigsaw cut the wood appropriately. Use the screws and drill or hammer and screwdriver to add needed legs to the cut pallets appropriately (this depends on the shape you chose). You will notice that my pallets are already a little modified (using a drill, a jigsaw, and wood screws). There is no need to make an Instructable out of that, I was just in desperate need for some more height on my bed. )
Step 4: Putting the Cover Back On
Then prepare your optional entertainment and sew the mattress cover back on by putting the cotton stripe at the edges of the side part and middle part of the mattress and sewing it through (the pictures explain it better - note that I took the sewing pictures after the sewing procedure was finished, sorry).
At all times make sure the side and middle parts of the mattress cover are straight and tight enough. If there's too much fabric on the edges, either trim them or fold them (towards the foam!).
When (after a few optional films) you reach the end, cut the extra fabric from the middle part and sew that together too.
And that's it, your foam mattress is now customised, nobody else has the same one!!
Sweet dreams :)