I want to do some multi exposures with 35mm color film - two overlapping images. I want one exposure to be more prominant than the other. I've never I've tried multiple exposures before - I just happened to come up with an idea while headed to an appointment today.

I'm not sure if this would be easier with print film or slide film - or about the same for both.

How do I figure the exposure for what I want - one exposure being lighter (more ?opaque?) and the other being more clear? Would it be better to do this lighter first, dark second, or the other way around, or it doesn't really matter?

Am I just having grand dreams - can it be done the way I'd like to do it? Is this pointless to even try when I have to rely on a lab to do the processing?

All advice is appreciated.