The patterns are actually determined by the 'Dither Pattern' setting on the engine itself (found under Additional Functions->System Settings->Device Management->Dither Patterns). The engine can have three patterns selected at one time, two you can change yourself. The two patterns are titled 'Resolution' and 'Graduation'. Changing the settings on the RIP just determines what objects on the page get tagged to print with what patterns (in this respect it might have been better to have called them 'Pattern1' and 'Pattern2' rather than Graduation and Resolution)
Eg, the default option in the EFI is 'Standard', this tags all text objects to print with the dither pattern that corresponds with 'Resolution' and all vector objects and raster objects to print with the dither pattern that corresponds with 'Graduation'. If you look under a loupe, you can see the different patterns on the same sheet.
If you select 'Graduation' then all objects on the page are tagged to print using the 'Graduation' pattern (whatever that happens to be set to on the engine)
Picking something like Pattern 3*, might tag raster objects to print using Error Diffusion (this is the engine pattern that is not configurable and is an error diffusion pattern), text object to print using the 'Graduation' pattern and vector object to print using the 'Resolution' pattern.
*Consult the EFI manual to determine exact combination.
If you generate a page containing text, raster and vector you can test for yourself to see dither pattens what the different Pattern1-7 on the EFI tag the objects with for printing.
Note that this does make the post from 'Color Printing Forum Admin' pretty redundant, as all the samples are raster (eg a photo) and it will depend on what the dither patterns are on their machine to how it prints. Eg if both the 'Graduation' pattern and the 'Resolution' pattern are set to 'Color Tones', then the only patterns the engine will print in are either 'Error Diffusion' or 'Color Tones', so on the EFI, prints made with 'Standard', 'Resolution', 'Graduation' will look the same, 'Error Diffusion' will be different and which ever pattern 1-7 that happens to tag raster objects to be printed with 'Error Diffusion' will be different.
Confused yet?
