Homebrew PCBs

Can any one say what are the easily avaliable photo checmicals to 
spray or paint on the bare pcb for either positive or negative print.

If not can we make from some bunch of checmicals.

I would appreciate instead of commerical name the checmical name to be 
given so that i can check with the chemcicals company which is 
avliable near by my house.

Regards

R.Pal