Layered ones? If yes, just use the console and type in:

!set x/y all (or any element) (value)

OR simply use the Property Edit Tool, set it to x/y, set its value (where it should be) , and click(and hold) the desired element.

@yocheese (View Post)
Another way:
1)Draw some photons
2)Draw another element over the photons
3)in the console, type:!set type phot xxxx
replace xxxx with an element.
4)You get an alloy of 2 elements.

this is not compress, it is layering.