Calculate Linux (Gentoo) using terminal dd comman to make a bootable ISO to USB stick.

I hope this will help anyone struggling to make a bootable USB stick from a ISO file.

Having said this, Absolute Linux ISO files are coming back as none bootable images (Etcher reported that)

check if sdd is your USB stick
with your own path and iso file

[BradHeffernan]

you can use

dd status=progress if=/path/to/iso of=/dev/sd?

the status=progress will show you the writing to drive progress as it does its thing.