Profiling...Been At this for a year, no luck

[Tovis]

First step should be finding the ink limits. Inks plateau at a certain point and by some phenomenon actually scan with less density if you over ink. The ink limit should be set to that plateau and this usually takes a while to find. You find this by printing the lin target, scanning it, looking for gradations to move up, not stay the same, and not to move downward. I’d start with the individual ink limits at 90% and move downward to find your ink limit. Be sure that color management and icc profiling is turned off when doing this.

The second step is to make a lin file by scanning that target printed with the magical numbers you found.

Install that lin and set the lin method you would like to use.

Next, you’ll want to find out the multiple ink limits and set a cap to where they run good without pooling or looking odd.

After that you’ll want to print the profile, scan it, and let whatever software you have make the profile. I use the substrate name to name the profile.

Profiling is an extremely finicky process. I have an i1 and ambient light throws it off or makes it difficult to scan substrates especially textiles. What I found is it is best to shut the lights off.

If you attempt to make a profile without finding the ink limits, or skipping the linearization process you are more than likely going to have a profile that doesn’t do so hot or has will have a limited gamut.

From time to time printers drift and this may need to be redone in the future.

 

[dayusmc]

I am a little co fused on the second step. You said make a lin file and install it. Not sure how to do this. I can print the linization file and scan it. So I think I am supose to start with 90% print it, scan it, look in the curves for each color and when they stop going up use that number as the ink limit for that color. When I have that part done, print one final chart and scAn it. From there I don't understand step 2. So turning the lights off when I scan works better? I will have to give that a try.

 

[Tovis]

can you save the lin file you scan once it is complete and install in your rip? or does it not allow you to do anything with linearization.

what rip are you using?

Yes, I had a heck of a time scanning colors with the lights on a lot of times it wouldn't even read strips. When it tried it with the lights really dim or even off it works almost every time.

 

[dayusmc]

I am using VersaWorks. Once I scan the lin t saves it in the profle I am creating. I always have a hard time picking the right values for the ink limits

 

[Tovis]

can you scan and look at the measured densities of each color your scanning.

for instance, can you look at the 100% magenta target scan that and and compare it with the next step down.

the densities should go up as you measure the target steps from 0-100%. If you see a plateau in the measured numbers or a point at which they repeat a bunch of times, that is probably going to be close to your ink limit. if they all measure ok you may need to go above 90.

Yellow is a funny color ink too because it is thin so it may not react the same as the other colors in this process.

it took me about a week to find ours. its probably the biggest pain of the process.

also, you may not even be close to the numbers you've been using before you started the process. in one of ours the numbers i set the printer at was about half what it was before. for another printer they had to all be set above 100%.

I'd say if you've never calibrated your equipment before, i'd start from scratch and learn the different settings and what they do along the way. Starting from scratch would mean not using existing settings simply because they are the status quo.

if you have any questions

tovis@printech-ads.com or feel free to use this forum