Help with how to make a zip off hood for a jacket

Looks like a stuffsack.
See what you have lying around- likely you could find one of about the right size and work off of that.

If you got nothing- look up a stuff sack pattern- or sew a round bottomed stuff sack- measure the crown of your head and sew a tube, then sew a circle shaped piece to close up the top.

The zip is going to leak like mad. Most uncomfortable around the neck as well. You have been warned!

Cheers

Looks a bit like a balaclava.

I have a zip off hood on my REI Primaloft jacket and have not experienced leakage or discomfort. Bot looking at the hood, it seems complex with the different panels and the drawcord in comparison to the rest of the jacket. I like the removable hood idea, I was just curious how it lays out. I thank everyone for your input.

I'm not into zip-off hoods myself (seems like a waste of weight for the zipper and you can't get as nice a seal around the face either) but if I was going to do one, I'd start by making the jacket with a nice collar and I'd sew one half of the separating zip into the seam between collar and jacket, on the outside. That's the way most removable hoods that I've looked at were done. That way, the jacket collar acts as a nice big baffle for the zipper when you put the hood on. Once you have the jacket made then you can prototype the hood for shape and pattern to mate with the zip., testing for fit with the jacket on.

> sew one half of the separating zip into the seam between collar and jacket, on the outside.
Yeah, that works.
But why bother?

Cheers

Good collar and a balaclava. Lighter, more versatile. No zip needed.

"why bother"

Because I want a zip off hood.