Hair spray as a fixative?

So I'm entering a health poster contest event for HOSA (Health Occupation Students of America) and they allow me to use non0senceted hair spray, an dI'm assuming it's for a fixative, but I've only heard of it only slightly, and I was wondering if I do use it as a fixative, can I draw over it?

Like, as if I were to have a line art of something, use the hair spray to fix it, would I be able to color over it again with something like colored pencils?

I could buy my own fixative, but the thing is that I don't know if I can bring my own, if I could, I would really consider buying my own, but since I'm limited to only bringing my medium, I can't chose my fixative

and in addition, outside this competition, what's the difference between matte and gloss fixatives?

I really only use pencils and colored pencils as a medium...

Hair spray as a fixative?

If you use colored pencils why do you need a fixative? If you used chalk or charcoal I could see why, but colored pencils are not going to smudge. Hair spray can work. Gloss is shiny, matt is dull.

Hair spray as a fixative?

be careful, i've used hairspray as a fixative before and it tends to discolor the page.

but yes, you could always colour over it, you just can't erase what's underneath. make sure it's complete before you spray it!

(and a tip: never spray fixative inside. i always step outside to do it, it produces horrible fumes.)