Yes, thank you, Jim! I did take into account the paper surface, but 
didn't think about the color space. I don't know if they know what paper 
they will print this on, so the separate channel may be the way to go.

I noted that several of their publication projects seem to use a variety 
of "377" so apparently this hasn't been a tightly-watched process in the 
past. I was just curious why all the variations.

I appreciate your color refresher course!!


On 2/2/19 2:14 PM, Karen Ackoff wrote:
> Jim,
> Good point about coated and uncoated papers. Also good that you raised 
> the issue of color profiles. Color is one of the more complicated 
> aspects of working with digital imagery. Great overview - thanks!
> Karen
> Sent from my iPhone
> On Feb 2, 2019, at 1:02 PM, James A. Perkins <[log in to unmask] 
> <mailto:[log in to unmask]>> wrote:
>> Hi Gail,
>> Sounds like you need to get more information from your client.
>> The most important question is whether they plan to print this job 
>> entirely in CMYK or if they plan to use the actual PMS 377 green 
>> colored ink. As you probably know, Pantone makes inks in a wide range 
>> of colors. These colored inks (also called spot colors) can be 
>> printed instead of CMYK. My favorite example is the FedEx envelope. 
>> The FedEx logo uses two very specific PMS colors, a purple and an 
>> orange. All of their envelopes are printed using the PMS purple, PMS 
>> orange, and black ink (for most of the text). There is no CMY. This 
>> would be a 3-color print job (black plus 2 PMS colors of ink). As 
>> Karen pointed out, it’s also possible to print a PMS color of ink 
>> in addition to CMYK - i.e., a 5-color print job
>> If they are indeed using the PMS 377 green ink, then follow Karen’s 
>> advice about creating a separate channel for that color in Photoshop. 
>> Anything painted on that channel will end up on a separate printing 
>> plate during the color separation process.
>> If they aren’t using the actual PMS 377 green ink, then they may be 
>> trying to simulate that PMS color using CMYK. I’m guessing that’s 
>> the case since they gave you a CMYK breakdown. Depending on the 
>> specific PMS color, the CMYK may or may not be very close to the 
>> actual PMS color ink. For example, if you tried to print the FedEx 
>> logo using CMYK, you could probably get pretty close to the purple 
>> but the orange wouldn’t be close at all. Most vivid neon colors 
>> can’t be reproduced in CMYK and require the use of spot color inks.
>> The other thing you need to find out from the client is what type of 
>> paper they are printing on. It doesn’t have to be the exact brand, 
>> but are they printing on coated or uncoated paper? Ink soaks into the 
>> fibers of uncoated paper. Better quality papers have a light coating 
>> on the surface that prevents the ink from soaking in. This can have a 
>> dramatic effect on the appearance of the ink when printed on 
>> different kinds of paper. For this reason, Pantone actually 
>> manufactures different inks for printing on coated or uncoated paper. 
>> When you select the color library in Photoshop or Illustrator, you 
>> have to specify if you want Pantone Solid Coated (PMS 377 C) or 
>> Pantone Solid Uncoated (PMS 377 U).
>> Because they are formulated differently, the coated and uncoated inks 
>> actually look different on screen, but should appear the same once 
>> printed on paper. The CMYK equivalents for the coated and uncoated 
>> inks are also different. This may explain some of the variation you 
>> are seeing in the CMYK equivalents of PMS 377 (although I just 
>> checked the Pantone color picker online and neither 377C or 377U is 
>> close to the numbers your client gave you. Odd).
>> There’s one other thing that can affect the CMYK equivalent of a 
>> Pantone color. After you select a PMS color from one of the color 
>> libraries in Photoshop, you can click on the “Color Picker” 
>> button and go back to regular RGB mode. If you are working on an RGB 
>> file, this will let you paint the equivalent of the PMS color in RGB. 
>> The hexadecimal value of the color (728f41) is just a different way 
>> of expressing RGB value. For example, hex 728f41 is the same as 
>> R=114 G=143 B=65. When you convert an RGB image to a CMYK file in 
>> Photoshop, the conversion of each RGB value to a CMYK value is 
>> controlled by the the RGB and CMYK Profiles you have selected in your 
>> Color Settings (under the Edit menu). A single RGB value (i.e., a 
>> single Hexadecimal value) can have many different CMYK equivalents 
>> depending on these color settings. Here’s an example:
>> I normally work with Adobe RGB (1998) as my RGB color space and U.S. 
>> Web Coated (SWOP) v.2 as my CMYK color space.
>> With these color settings, a Hex value of 728f41 is equal to a CMYK 
>> value of 66  24  100  7.
>> Then I go back into Color Settings and change the CMYK profile to 
>> U.S. Sheetfed Uncoated v.2.
>> I reopen the color picker and, even though the Hex/RGB values are 
>> still the same, the CMYK values are now: 64  16  100  7
>> Not a huge difference, but still a difference. This subtle difference 
>> is all because of the difference in printing technology between a 
>> sheetfed press printing on uncoated paper vs. a web press (SWOP) 
>> printing on coated paper.
>> Probably more information than you needed, but is underscores why you 
>> need more info from your client and why it is that CMYK values can 
>> vary even when the PMS or Hex number is the same.
>> Jim
>> James A. Perkins, MFA, CMI, FAMI
>> Board Certified Medical Illustrator
>> Fellow, Association of Medical Illustrators
>> Professor and Graduate Director
>> Medical Illustration
>> College of Health Sciences & Technology
>> Rochester Institute of Technology
>> CBET 75-2129
>> 153 Lomb Memorial Drive
>> Rochester, NY 14623
>> [log in to unmask] <mailto:[log in to unmask]>
>> ------------------------------------------------------------------------
>> *From:* SciArt-L Discussion List-for Natural Science Illustration- 
>> <[log in to unmask] <mailto:[log in to unmask]>> on 
>> behalf of Gail Guth <[log in to unmask] 
>> <mailto:[log in to unmask]>>
>> *Sent:* Friday, February 1, 2019 6:09 PM
>> *To:* [log in to unmask] <mailto:[log in to unmask]>
>> *Subject:* Re: [SCIART] a Pantone color question
>> Good info, Karen! My fan set is ancient, I almost never use it so I 
>> don't bother with updates; Photoshop is up-to-date. thanks for the 
>> separate channel suggestion!
>> Gail
>> On 2/1/19 5:28 PM, Karen Ackoff wrote:
>>> Pantone color sets are updated every year. How old is your set? Or, 
>>> how old is Photoshop? Be sure to tell the printer that you are using 
>>> that specific color. You need to make sure you have a channel set up 
>>> for the color. That way, regardless, the printer can separate out 
>>> that color as he’ll need to ink the press with Pantone 377. 
>>> So if the file is CMYK, it will be CMYK plus Pantone 377 - a 5-color 
>>> run. Won’t matter what it looks like on screen (which 
>>> isn’t going to match any way - your monitor is RGB).
>>> K
>>> Sent from my iPhone
>>> On Feb 1, 2019, at 3:00 PM, Gail Guth <[log in to unmask] 
>>> <mailto:[log in to unmask]>> wrote:
>>>> Hi, Everyone -
>>>> I'm doing a small job for a client, and need to match their 
>>>> official color, which is Pantone 377. She gave me CMYK numbers as 
>>>> well: 47-7-76-0.
>>>> In Photoshop, entering those CMYK values in the color picker 
>>>> produces a much lighter green than I am seeing in their printer 
>>>> materials, and lighter than what I'd like to use.
>>>> When I go to the Color Libraries and choose Pantone Solid Uncoated, 
>>>> and enter 377, I get the deeper color I want but the numbers are 
>>>> quite different (60-27-95-8, hex 708f41).
>>>> I went online to the Pantone Color picker and entered 377, I got 
>>>> the deeper green with the same hex number but a different CMYK 
>>>> value again, however it is somewhat similar to the CMYK values my 
>>>> client gave me (45-0-100-24)
>>>> I am confused. Why all the variation? I'll end up choosing the 
>>>> deeper green but I don't get all the different numbers.
>>>> --Gail
>>>> -- 
>>>> Gail Guth
>>>> Guth Illustration & Design
>>>> 139 Lathrop Avenue
>>>> Battle Creek, MI  49014-5076
>>>> 269-963-1311
>>>> [log in to unmask]
>>>> <>m 
>> ________________________________________________
>> Need to leave or subscribe to the Sciart-L listserv? Follow the 
>> instructions at
>> <>
> ________________________________________________
> Need to leave or subscribe to the Sciart-L listserv? Follow the 
> instructions at
Gail Guth
Guth Illustration & Design
139 Lathrop Avenue
Battle Creek, MI  49014-5076
[log in to unmask] <>

Subscribe to Sciart-L by completing the form at

List name is Sciart-L

To unsubscribe, complete form at

Problems: Email Lana at [log in to unmask]