CHROMiX

Indigo

Would like to hear about anyones experiences with Color and ColorManagement on a Indigo. What their feelings are as far as the product it produces compared to offset.

Variable data which programs are you using and why

Hello Mike,

We only have HP Indigo presses in our company. Our customers often send us press sheets from local printing companys, and want us to reprint or match the companion piece.

In my opinion the quality can be achieved. In some cases the color and consistency is more consistent than traditional printing. We do use color management and process control to elevate the print quality off the indigo presses.

Because the size of liquid ink is 1 to 2 microns in size, and the blanket temperature is around 350 degrees, the ink conforms to the substrate’s surface. This is different than toner because of the size of the toner (dry ink). The toner can only be 7 to 10 microns in size. If it were smaller the press could not controll the toner. Since the toner is larger than the Indigo liquid ink, it takes on a look other than the substrate’s surface.

The Indigo uses only AM screening, we use 175 line screen. I run TAC around 320. I can hold a 1% dot on all substrates: gloss, dull, matte, uncoated. The print contrast is usually a little higher than traditional printing due to the fact that the ink does not penetrate the substrate.

We run the commercial press at a 2 delta E tolerance from sheet to sheet.

As far as variable data printing, we have found it really depends on your customers. We have a good mix of static printing and variable data printing. Direct mail, versioning, barcoding, and promo pieces are the biggest users of variable data. Its more than black type changes, the designs are four color changes with text and images changing every piece.

If you have any other question just contact me.

I’ve got a few question as well…

When running to simply match traditional printing, do you find it necessary to always use color manament (input, output and emulation profiles) or do you just tweak density and dotgain to get a ball park match. Are you using the supplied HP profile or did you create a custom one? Do you use this device for proofing as well?

I noticed a “Sequin” option within the screening selection, what LPI does this relate to?

Sorry it took me a while to respond Michael;

If the traditional sheet has a supplied profile with the job or I am able to get their profile, then yes I use input/output in the Production Flow RIP Station (HP Off-line RIP). When you ask if I “always use color management”, maybe I was not being specific enough. If I only get a supplied press sheet from an unknown source with no profile, then I run our HP Indigo press to our target numbers, then I read several areas on the traditional sheet (try to find solids and a midtone color) with Color Picker with my profile selected. I write these down and then read from the same spots off of my Indigo press sheet. Then I adjust the SID and TVI. This gets me very close with limitation of saturated hues. So I am still using profiles to help me narrow the gap. We also use Measure Tool.

We create custom profiles.

Yes, the color gamut of traditional printing and the HP Indigo are almost an exact match. The electroink’s Lab values in the SID are similiar to the values posted in GRACoL 7. You can see how close they are in Color Think.

The resolution of the engine is 812.8005. This allows for a AM screening of 144 (Sequin). The other line screens offered are emulated from Sequin. This is the information I got from our Field Service Engineer.

There are still some issues like banding and running just any paper through the press. The banding is always there but some designs and color hide it better than others. The substrates should be tested to ink anchoring and run ability.

We are in the process of upgrading to the latest commercial Indigo press which improves these known issues. If you would like send me a sheet with your profile and I will apply both workflows for your judgement.