Making bench cushions

[jessiematfield]

Hi, I want to make bench cushions from polyester instead of foam so that they are more "giving" under the knees i.e. not that stiff edge that foam sometimes give. The lady who is making them for me is having trouble sourcing the 'material to make the inners. Is it me? Have I asked for something inappropriate? What has everyone else used? I'm not really a crafty type, the garden is my domain so am a but out if my depth. Thanks all xx

You can get polyester cushion filling from Amazon or eBay.
The problem I think you may have with a long bench cushion (presuming that's what you want her to make) is that the stuffing will just flatten when you sit on it and not be very comfortable in a very short time. Either that, or, it will redistribute itself inside the cushion and become lumpy and uncomfortable.
Would a softer, thinner, upholstery foam not be suitable?
You can get such a thing from eBay and can order a variety of thicknesses from 1 inch up to whatever.

Can the foam be wrapped in wadding or something else. How firm a foam is it to have a hard edge under the knees?

I'm not sure what you mean by polyester. Do you want it to feel like a duvet, or a throw cushion? If not, then what?

When you buy foam you can have it wrapped in stocking stuff, which avoids having a sharp edge. As wowfudge says you can also wrap wadding round to soften the edge and give a more luxurious look. I think this is probably a better option than trying to do the whole thing without foam - unless you want to feel that you're sitting on a duvet.

If it's too floppy it'll squish down flat when you sit on it. You'll feel like you're sitting straight on the bench, like sitting down on an underinflated airbed, plus you'd need to replump it regularly. You need some resistance from the foam so it's actually cushioning you.

We have cushions that have a foam core with polyester filling round, but they are back cushions for sofas. Various online places do mixed filling cushions with a foam core, eg this one though it's feather than foam:
www.originalticking.co.uk/bespoke.php

However there does need to be enough central "resistance" especially in a cushion you sit on, so it feels comfortable. And generally with a bench cushion you don't want to be replumping, you wnt something that regains its own shape, which foam is excellent for.