Come on you handy DIYers, help me out..

[BirdieBootie]

I want to make an artwork to hang on the hall wall & I need a canvas at least 3ft x 4ft wide, possibly even a bit bigger. How can I make it? It needs to hang on a modern stud wall so can't be too heavy. I didn't want to just paint on a slab of mdf as I want to make a floating frame around it like the one in this pic. Any ideas how best to make it and then fix it up discretely?

What I mean is, I want to paint the picture myself & need an appropriate surface that I can then frame as above.

The Works often have large canvases for sale. I am not sure if they will have lost them to make way for Christmas things yet though.

You could try Jackson's Art OP www.jacksonsart.com/search/?fq%5Bsurface_imp_xandy%5D=36+x+48+in&q=canvas Probably best to ring first and check if there are additional postage charges for oversized items.

Go on YouTube and put in the search box how to make an art canvas. Then search for how to create a floating frame for canvas.
Wasn't sure from your OP if it was the frame you wanted help with or the canvas itself.
Both are there and look reasonably simple.
Famous last words!

You can of course make your own canvas to any size and spec you want but by the time you've got your stretcher bars, stretched the canvas and primed it, you might as well just buy it. I only really do it these days if I need a very large canvas or one that doesn't conform to readily available sizes. It's fun to do though and relatively straightforward after a bit of practice.

Readymade canvases also come in different depths, you will need a narrower depth canvas for a floating frame.