Get ready for a possibly daft question....

What is bulb fibre? Obviously, fibre that you mix in with compost for bulbs, but where does it originally come from? Is it the same thing as coir? Will any sort of shredded fibrous stuff do the job?

I've just started out on bulbs, bought some cheapies at the garden centre and will be looking at potting them up for inside use next winter/spring.

All knowledge gratefully received....

Thanks, Bob