Professor Jim,

You know So much about so many things!  Thanks for your insightful 
dispatches--I always learn something new from you.



On 2/2/2019 11:02 AM, James A. Perkins 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]> on behalf of Gail Guth 
> <[log in to unmask]>
> *Sent:* Friday, February 1, 2019 6:09 PM
> *To:* [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 
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*Chris Gralapp*,MA, CMI, FAMI**

Medical/Scientific Illustration

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