QTR + MIS Carbon inks: Banding-Free Gradients ?

[Ken Lee]

Hi Sandy - I have worked with Richard Boutwell quite a bit. He's a great guy. The best profile I have made, was done with his help.

In the end however, I was unable to entirely remove banding. Ultimately (I'm paraphrasing) he suggested that I was getting about as good a profile as can be expected with the tools at hand. I took this to mean that any further refinement would involve adjustments to the final .quad file - which would require a higher grade of measuring tools and mathematics than I possess.

The banding I'm describing is not blatant or apparent throughout the tonal scale: it appears in only a few places. Most of my prints look lovely and after working with Richard Boutwell I thought I'd give it a go with some of my most demanding images, like this one: except for a few sharp edges, it's nothing but gradients.

On a related note, when I contacted the makers of my spectrophotometer in Switzerland, they told me that its inability to deliver a consistent read-out from the same sample was "normal". I could understand if we were talking about measurements down at the level of quantum uncertainty, but a simple LAB reading from a sheet of paper shouldn't be rocket science.

[Ken Lee]

I still wonder: if .QUAD files specify only 256 values for each channel (8 bits), how can we expect 16-bit fidelity ?

[Ken Lee]

Update: I made up a test image consisting of a the aforementioned 51-step bulls-eye gradient and a few other challenging photos - then ordered a print from Cone Editions, using their pure Carbon inks and 100% rag paper.

The print is perfectly linear: no bumps, no banding, no blemishes of any kind. Perfect.

End of story for me.

[Peter De Smidt]

Ken, how's the print tone?

[Ken Lee]

I'm very happy with the print tone. It's warm, but I like it for most of my subjects.

They made the print on an Epson 3880 with K7 Carbon inks on Hahnemuhle Photo Rag 308gsm - a paper I have not previously used.

It's very similar to what I get on Premier Smooth Hot Press Fine Art Paper.

If perfect linearization weren't enough, the other factor to consider with InkjetMall and Cone Editions is their superb and prompt customer service: the difference is truly staggering.

[Peter De Smidt]

Ken, thanks for the feedback. I may make the plunge myself this fall.

[Ken Lee]

Additional update with further good news:

I ordered custom K7 Carbon profiles for my printer for 2 papers. They were made and emailed back to me in very quick time.

I just made test prints using these profiles and the results are just like the sample print they sent me: perfectly linear.

My old approach was to use a consumer-grade spectrophotometer, measure 21 steps and interpolate the points. Basing a profile on 21 measurements amounts to little more than 4-bit accuracy, so it's no wonder there was banding and irregularity which could not be adequately smoothed.

I found it's much more effective to let experts use professional tools to measure 256 steps and linearize.

Now I can finally make faithful prints of images like this one:

[sanking]

Ken,

Beautiful print. Congratulations on finding a solution that allows you to make such great prints from these delicate images.

Sandy

[williaty]

To clarify, you printed out a file Cone sent you, sent it back to them as a print, they read the print, and sent you profiles?

[Ken Lee]

Yes. You download a 256-step target, then print it using one of their existing profiles. You send them the print and the profile, they measure the print, adjust the profile to exactly suit your printer, and send you the profile.

Apparently they are in the process of developing a tool-set which will allow you to do this yourself, provided you use one of spectrophotometers they support.