How to attach cushions!

[Miljah]

I have 4 metal directors chairs. I want to make 4 seat cushions out of 2" foam, possibly covered in corduroy. My question is: how can I attach them to the existing blue sling seat? They're not removable so I'd have to attach in situ.

My only thought was to make 4 tabs with a button hole in each, sewn onto each corner of my new cushions and to sew 4 big buttons to each corner of the sling, underneath to button the cushions on.

Previously I tried Velcro but I had to hand sew one side to the sling as, being non removable, I couldn't machine them and the hand stitching kept breaking as people's weight inevitably dragged the cushions forwards.

Any thoughts?

Strips of wide elastic? I know you can get narrow elastic with buttonholes in it, not sure about wider stuff though.

I think your tab/buttons/buttonhole idea will work.
The only suggestion I can add to that is to make sure the tabs are a little longer than they need to be. This will allow some movement in the cushion when it is sat on, thus not causing too much tension which would pull at the buttons.

Thanks, good ideas!

How good is your hand sewing? I would possibly consider some heavy weight linen thread (with an equally heavy weight cord and a strip of webbing inside where you're sewing to add strength, so you'd be stitching through both cord and webbing) and sew 2 rows of stitching.

You'd need a good thimble and a fairly hefty needle.

Could you put a tie on each corner of the cushion and tie them onto the frame?