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CHROMiX ColorNews Issue #72 - Beginner's Cheat Sheet

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  CHROMiX ColorNews
   Issue #72 - July 1st, 2020

This Month's Contents

  1. CHROMiX News
  2. Latest blog entries in ColoRants (and Raves)
  3. Shows and Events
  4. Color Industry News
  5. Forum Topics, Random Bits, etc.
  6. Article - Beginners Cheat Sheet
  7. CHROMiX Open Box items for sale
  8. ColorNews Admin (feedback, subscriptions, etc.)

CHROMiX Blog
For the very freshest color updates, check out our blog Colorants (and raves).

Respond & Discuss
Don't forget, you can discuss this month's article and anything else from this newsletter in ColorForums.com

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Find full details about subscriptions, etc at the end of this newsletter.

CHROMiX News What the heck have we been up to?

Uncertain Times

Last ColorNews issue, #71, we addressed the COVID-19 pandemic and dared to hope that things would be starting to get back to normality by this time. Instead, we find ourselves amidst an important moment of societal upheaval and change, and it goes without saying that these larger issues permeate not just our personal lives, but our professions as well. We are our most vibrant and successful when every color of the spectrum shines. That's work we get behind.

This month's article

Pat Herold goes back to basics this issue with his article titled 'Beginners Cheat Sheet'. In it he offers an easier way to think about (and understand) the three L*a*b axis in a modern graphing tool (most notably ColorThink) as well as different ways to think about the rendering intents for mapping in and out of gamut colors.

Curve4

We've just released another beta of Curve4 4.4. We were very close to getting to final and Catalina threw us a few curves (so to speak) and we were also able to include support for the new i1 iO3 scanning table.

So, one more round of beta and we'll get it out in final form within the next month or so.

Thanks everyone for all your feedback

CHROMiX LinkedIn Page

Check out the latest with our LinkedIn page. We consistently update this with fun and useful stuff.

 

CHROMiX Blog Here are some of the recent posts to our blog: Colorants (and raves)

  • CHROMiX Blog - If you are not aware, CHROMiX has a regularly updated blog that we try to keep light and topical. Check it out!

Shows and Events Color-relevant gatherings to plan for

September 15th - 17th, 2020 - LABELEXPO Americas, Donald E. Stephens Convention Center, Chicago, IL. Still on.

October 21st - 23rd, 2020 - Printing United, by SGIA. Georgia World Congress Center, 285 Andrew Young International Blvd NW, Atlanta, GA. HAS BEEN CANCELLED, but has been replaced with a 'powerful online experience'.

October 1st - 3rd, 2020 - Techtextil North America. Atlanta, Georgia. Still on, new earlier date.

January 23rd - 26th, 2021 - COLOR21 Conference, La Jolla, CA at the Hilton La Jolla Torrey Pines, CA. CHROMiX will be there and we look forward to this event as always! Register here.

April 20th - 30th, 2021 - DRUPA (Rescheduled from April 2020). Dusseldorf, Germany.

Events Calendar: For all current and future events, bookmark this calendar.

Color Industry News What's going on in the world of color

Guide to Print Production, Update 20.1 released

The updated guide contains 112 pages of critical information that stakeholders in printing, packaging, and design need to know to provide high quality color accuracy and improved workflows.
The Guide to Print Production originates from Idealliance. It includes new specifications, standards, leading practices, how to guides, certifications, and critical advancing information that moves businesses forward in efficiency and profitability.

Go here to get your free copy!

We highly recommend this guide for everyone, experts to novices.

Idealliance new Board, Officers and CEO

Idealliance announces a new Board of Directors and Officers for 2020-2021 Term.
Among them, Dick Ryan was appointed the new CEO replacing Tim Baechle.

Konica Minolta Sensing reshaping tools family

A few Konica Minolta instrument tools will be added to a new family of products called 'MYIRO'. The MYIRO-1 hand-held spectrophotometer was announced this last Fall. Later this Summer the familiar FD-9 scanning spectro will be discontinued, renamed the MYIRO-9 and then will be shepherded into the MYIRO family completely the same except for the MYIRO logo change. There is no cause for alarm for any FD-9 users, but you should be aware that once discontinued, FD-9 parts will be officially available for only 7 years. KMSI will continue to support and warrant product as normal, and of course, CHROMiX will continue to support and help our FD-9 customers indefinitely. CHROMiX will be selling the MYIRO family of products also.

Forum Topics and other bits  Popular topics from ColorForums.com and other things we've found along the way.

Dare you question D50?!:   And yes, you should. Very good article in WhatTheyThink about D50 by Abhay Sharma.

HP Stich S500 versus Epson SureColor F6300:   Our friend and longtime dye-sub guru Perry Schwartz (VistaLogics) does a great job comparing these two models. Notable (for us) was his extensive use of Curve4.




Beginners Cheat Sheet by Pat Herold

There's so much to learn when learning color reproduction that we've decided to offer this short article as one place for newcomers to learn some basics. These are colorful shortcuts to help understand some basic concepts and keep them in memory.

How to estimate L*a*b* colors

We have written about Lab space in previous articles. There are times, when looking at a Lab number, that it would be useful to get an idea of the color it represents just from the digits alone. Fortunately, it's possible to do this pretty easily. There are 3 axes in Lab: the L* axis represents Lightness or Luminosity from 0 to 100, so that is easy to remember: The higher the L* value, the lighter the color sample is.

But what about the a* and the b* axes? Let's start with b*

b*

The b* axis is best considered by remembering that it moves exactly the opposite from what one would expect. With a letter like B you'd expect the plus values to be more blue and vice versa. But actually this is not the case. In Lab space, minus (-) b* values are more toward the bluish range of colors, and positive (+) b* values are warmer, more toward the yellow. Just remember that with b* and blue, it's the opposite of what you would think, and you should be in good shape.

a*

The a* axis requires a more colorful memory trick.
Negative (-) a* moves in the direction of greenish-cyan, while positive (+) a* represents reddish-magenta.

Think of the a* axis as the "apple" axis. On the negative side we have the green Granny Smith apples, known for their tartness. Not very tasty, thus the negative. At the other end of the spectrum, on the plus side, consider the beautiful "red" Red Delicious apples. Yum! That's a plus in anybody's lunch box. This apple appraisal is even borne out scientifically. An informal poll of color management experts at the CHROMiX headquarters revealed that 100% of the sample group considers Granny Smith apples to be sour and distasteful. There you go.

If you don't share our same sense of apple classification, you can instead think of the a* axis as representing our vertical positioning on the planet. Minus (-) is down and plus (+) is up. Green is the color of the land on earth (at least it is with all the weeds in my backyard at the moment). That's down, or minus. But red is the color of the sun, way up high. Plus values move to the reddish end of the spectrum.

Before we leave this topic, please note that while it's easy to fall into calling this the green-red axis, the actual colors on the axis are more of a greenish-cyan to a reddish-magenta.
There is a myth concerning this which we wrote about in issue 16 of the ColorNews.


How to explain Rendering Intents


Another challenge to the neophyte in color management is understanding rendering intents. While there are four rendering intents when using a profile to print, the two that are most often used are Perceptual, and Relative Colorimetric. To someone who hands you an image and says "I just want it to print correctly," you don't really want to launch into a long explanation describing transforms and lookup tables and Profile Connection Spaces. But you can explain that they have options about what should be done with colors that are outside of a printer's ability to print.

Here are a few analogies I have found useful:

There are different ways to take an object and make it smaller when necessary.
For my final project in wood shop in Junior High, I chose to make a bowling ball out of wood. I glued together several different exotic blocks of wood and then turned this big, blocky mess on a lathe to trim off the excess portions until it was round. I basically had a specific gamut in mind and trimmed off everything that was outside of that gamut. This is somewhat analogous to the Relative Colorimetric rendering intent. ( I realize it's an imperfect analogy. To be a true Rel Col RI, all the wood outside would have to be squished and pressed until it were moved to just within the circumference of the bowling ball. But let's not get too technical; come on - work with me here...)

The Perceptual rendering intent is analogous to a balloon. Think of a balloon with a pattern of stars on it. When fully inflated, the stars are in a certain position. If some air leaks out, the balloon gets smaller and each of the stars move closer to the center of the balloon. The relationship between each point on the balloon remains the same, but the gamut of the balloon gets compressed.

If there were a picture of Mickey Mouse on the balloon, the picture would continue to be recognizable as the balloon got smaller, because the relationship between each point on the surface would be retained as each point evenly moved closer together. Not so for the bowling ball. If my original glued blocks bore a resemblance to Mickey Mouse when I started, then much of the original would be cut off as I trimmed it down on the lathe. There go the ears! That's what we'd call "clipping of the gamut."

Naturally, the choice of these rendering intents depends on one's intent for the image. If it is more important that the relationship between all the colors be retained, then Perceptual is the way to go, while understanding that many of the colors will be desaturated. If the greater importance is to maintain the most saturation in the colors, then choose Relative Colorimetric and accept some clipping of the out of gamut colors.

When learning new concepts, it helps to be able to bring to mind concrete visual images. But whatever you do to learn, don't stop learning!


"Education never ends, Watson. It is a series of lessons, with the greatest for the last."
      - Sir Arthur Conan Doyle


Thanks for reading,

Patrick Herold
CHROMiX, Inc.

   To read this article with images in ColorWiki, click here

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