In June 2022, Adobe announced the release of the next-generation Adobe PDF Print Engine (APPE). This print engine is the industry standard for interpreting PDF artwork files, and it's licensed to many printer and software (DFE/RIP) companies — Epson, HP, EFI, ONYX, Caldera, and more. The licensed APPE also includes Adobe's Color Engine (ACE), which enables automatic color conversions of RGB, CMYK, multichannel (nCLR/ECG), and spot color images and elements in PDF documents. APPE v6 brought major, significant advancements — and one of them is a genuine milestone for anyone who cares about spot color. APPE v6 can now interpret spectral definitions of spot colors to reproduce spot color tints and gradients. This is BIG. Here's the context. The master digital definition of any color is spectral. The LAB values everyone uses are derived from that spectral definition for a particular illuminant, observer angle, and M measurement mode — which is how all the Pantone libraries are distributed. But those LAB values only define the solid color (100%), and carry no transparency information — and spot color inks aren't totally opaque. Designers frequently overprint spot colors in their artwork, and there was no way to interpret this properly without spectral definitions. On top of that, the LAB values for a solid color include no tint information — and many designers don't use only 100% solids, but tints and gradients, sometimes overprinting one another. The ability to define a full-characterization spectral color — one that defines all the tint values and transparency — has existed for years (see the ICC's material on ISO 17972-4:2018). But most DFEs and RIPs couldn't make use of it, because it simply wasn't supported — until now. This is critical functionality for reproducing and matching spot colors accurately, especially overprints and tints. This also tails — pun intended — right into what's happening with PDF 2.0 and PDF/X-6, a topic my colleague Dr. Dov Isaacs explained very well in this presentation. No — well, it's kind of a trick question. Pantone's master definitions are all spectral, but you can only reference them in their PantoneLIVE platform via subscription. The libraries included in Adobe apps and other software like RIPs are not spectral. Yes. The one I'm most excited about — really excited, I know, I'm a ColorGeek, I can't help it — is called ChromaSpot. It's an open-architecture, substrate-independent, free, all-spectral library available to download and import. You can read more here, and I'll be doing a dedicated post on it. Yes — the key word being "may." With a free, all-spectral library like ChromaSpot available to import, you may not have to measure and define your own colors. You use an instrument and software to measure the color from any object or swatch. I'd highly recommend reading my post on ChromaChecker Capture for this. There are options, but CxF is the ISO standard. Datacolor has their own proprietary QTX format. Both ACB (Adobe Color Book) and ASE (Adobe Swatch Exchange) can save color libraries, but they only support Lab, RGB, and CMYK values — not spectral. So you keep your master lists in CxF and convert copies to ACB or ASE for use in Adobe CC. If you need libraries to show up in Channels, you must use ACB. I use a powerful module called Coraye Color Table to import and export color tables to whatever format I want — more on that on our store. No. Adobe still doesn't support spectral definitions or CxF files in CC apps, so you'll need to convert the CxF to ACB/ASE first, then import. Once you have a spectral CxF definition, you have options: Before you get too excited, know that the list of software supporting the new engine started short. Caldera was among the first out of the gate, shipping APPE v6 in its version 16. Other RIP manufacturers have been rolling out APPE v6 support in the time since — but how quickly each vendor adopts it, and how they choose to implement the new functionality, varies. In every case, a new implementation needs to be tested and proven to work properly. Either way, this is a big announcement and a significant technological advancement — something you should be aware of and planning to take advantage of. If you need help doing that, don't hesitate to reach out. Questions about spectral spot color or APPE v6? Get in touch. Director of Technical Services, Alder Color Solutions Dan has spent more than three decades helping printers, converters, publishers, packaging companies, and photographers get control of their color — across offset, flexo, wide-format, digital, and packaging production. He founded the color consultancy ColorGeek Inc. in 1999 and joined Alder in 2018. A certified G7 Expert since the inaugural 2006 class, he has spent nearly twenty years implementing G7 and international print standards in real production environments, and was one of the few certified instructors for the SGIA Digital Color Professional program. He's also a professional photographer — which keeps him fluent in both the artistic and technical sides of imaging.
The Big One: Spectral Spot Color Definitions
Why This Matters for Tints and Overprints
The Questions You're Probably Asking
Do the existing Pantone libraries include spectral data?
Are there other color libraries that include spectral data?
Does this mean you may need to measure/define your own colors?
How do you create a spectral color definition?
What file format do you save the spectral definition in?
Can you import a spectral CxF file directly into Photoshop?
What You Can Do With a CxF File
Which Software Actually Supports APPE v6?
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dang@aldertech.comAbout the Author
Dan Gillespie