Profiling Step-by-Step

[Chris Halt]

Can anyone recommend a source for step-by-step printer profiling for the noob?

I am trying to profile an EPSON printer using Colorport with an iSis spectrophotometer and MonacoPROFILER.

No problem printing the it8 random target without CMS from PhotoShop.

No problem scanning and saving Monaco session data through Colorport and iSis.

No problem generating a CUSTOM profile through MonacoPROFILER.

I drop the CUSTOM profile in the ColorSync directory and it becomes available in PhotoShop and that is what I use to print a confirmation target.

I then scan the confirmation target and expect it to be reasonably close to "the" standard but it is not. As a matter of fact the numbers are nearly identical to the first round linearization.

Here is the resulting data from confirmation scan using custom profile:

Average delta E: 30
Average delta E 94: 22
Average delta E CMC: 13

I'm sure I'm missing something.

Thanks for any help...

[TerryWyse]

You mentioned printing an "IT8" target which I assume to mean a CMYK IT8.7/4 target.....since you didn't mention using a (CMYK) RIP such as ColorBurst or similar, that's most likely your problem. If you're printing via the print driver (no RIP) then you must profile it as an RGB device despite the fact that the printer has CMYK+ inks.

Start over and use the Monaco 1728 patch RGB target and you should get better results.

Now, as far as comparing to a "standard", what exactly are you doing and what steps are you taking to print your standard? First off, I would probably NOT recommend using any of the standard RGB working spaces as a standard/reference. Even sRGB is likely to have regions of color that are out of gamut for your printer+media, enough that you'll likely see fairly high delta e numbers. A better standard that is more likely to fall in-gamut for your printer would be either GRACoL Coated1 or SWOP Coated3. These are both "standard" CMYK press targets that should fall reasonably in-gamut (yes, you can print a CMYK target through an RGB profile...it's only the initial printer profile that must be RGB if you're printing via the print driver).

You also mention "linearization" but you didn't indicate you're using a RIP. Linearization is almost exclusively the function of a RIP and it's done PRIOR to profiling....it's not unlike the calibration process you put a monitor through prior to profiling the display.

With a little more info I think we can help you better.

Regards,
Terry

[Bloodsaler]

Does your proof device calibrated?I do this experiment through EFI Colorproof Program