Make your own diffraction gratings

[Ref]

Does anyone know (or is there a guide) how to make your own diffraction gratings? You can get the film from rainbow symphony, but I guess my question is..can the film be layered on top of each other to create a more exciting effect? Something like the different types of matrix gratings that nova sells. How would you go about making the mega matrix as compaired to the regular matrix?

I have a laser star projector that seems to be made out of several different gratings placed together, but Im afraid to take it apart to see how it works.

 

[desslok]

I woul dbe interested too. Just be sure to get some proper goggles before experimenting, as you never know which direction a beam is going to go and bounce off of something.

 

[Ref]

I know. I have some goggles that are >OD6, so they hardly let you see the dot, much less the beam, so I need to invest in another pair.