Is RGB to Printer for the CMYK conversion best?

11+ years as a graphic designer and I’ve always created CMYK for Print and RGB for Web…however I was noticing that everyone I came across on YouTube (regarding Etsy) saves their print designs as RGB before zipping them up and placing them on their Etsy account for purchase. I was confused by this. Then I found a video from Printful (a printer) that said it’s best to send in an RGB file because (as we know) it has the best color range and that a printer will always convert it to CMYK and ‘match’ the colors as best as they can to look more like the RGB file sent in. I also read where someone did a test and had a CMYK printed and an RGB converted to CMYK at the printer printed and the RGB looked best. Is everyone doing this now? Is this the best practice, or too much of a RISK? Just wondering what you all do or think about this. Thanks!

1 Like

It’s been a long time like this.

1 Like

Converting to CMYK used to be a necessity, but now it depends on a number of variables.

For digital printing, RGB is usually best because most digital printers use six or more colors of ink, so the color gamut is larger than with only CMYK. Because of this, letting the printer RIP make the conversion to however many colors their printers handle is usually best.

For offset CMYK work, it gets more problematic. Yes, many offset RIPs will convert the RGB on the fly to CMYK, but doing so takes away your ability to make sure the CMYK conversion is what you want. For example, if you send an RBG file with black text, the RIP will convert the RGB to a rich CMYK black instead of 100%K. On the other hand, if you send a CMYK Illustrator file with 100%K text but with placed RGB photos, the RIP will keep the text 100%K while converting the photos to CMYK on the fly.

I still prefer to do the RGB to CMYK conversions myself when I’m in doubt. Part of the reason is that I’ve done it that way for years and don’t quite trust changing the routine unless I’m sure the printing company can handle it. When I asked various printers about it, I’ve gotten different responses. Many offset printers I work with have told me they don’t want RGB files.

All too often, clients think they can save a few dollars by lining up the printers themselves. They typically don’t know one printer from the next and underestimate their ignorance, but when they insist, I send them only CMYK files since any printer (including digital printers) can handle them.

And speaking of ignorance, there are people here more deeply involved in actual printing than me, so you’ll likely see a few people disagreeing with me or providing details that I don’t have.

Just to expand on what B has said.

If you have images from different sources - like RGB from stocksites, for example.
You would in the past go into photoshop and convert this RGB image to CMYK.

However, Adobe and other apps can do this same conversion on the fly from the PDF conversion - and it’s the same conversion that Photoshop or similar apps would give you from CMYK to RGB.

The days of holding a RGB image for the web, a CMYK version for print etc. are long gone.

Use the same source file across many different devices.

This is simply because you don’t get any gains - unless you’re specifically being controlling of the CMYK output.

For example, for a art gallery.

When you convert RGB to CMYK - CMYK has many different outputs - digital, litho, etc. and many different Colour Profiles, US Web Offset - Euroscale Coated, Uncoated

All each changing the colour the fit that profile and suit that printing method.

You’re best advantage is to leave all your colours as RGB, sRGB, Pantone, CMYK (from any source)
Place these in your files

When exporting to PDF for print - use PDFX4a - which retains the colour - it does no conversion.

RIPs often come with built-in color management tools, including the color lookup tables (LUTs), to ensure accurate color reproduction on different types of printers.

When I deal with amateurs or amateurish software when it comes to print I provide sRGB.
A lot of office printers expect RGB and don’t leave CMYK alone so you e.g. don’t get 100% K Text anyway. I struggled to get MS Word to print CMYK properly and failed.

When I deal with pros I provide CMYK or combined CMYK and RGB. RGB solo I’d only provide for textless images for printers with wider gamut.

by the way sRGB does not cover Fogra39/ISOcoatedv2 gamut completely.

For 90% of my work, I still convert to CMYK. I do a lot of illustrated trade titles (coffee table books with strong, rich imagery). Many are books with of artworks and objet d’art that need to either be colour accurate, or that I need to control the colour of, based on a number of factors.

For example, one author who I work with always wants the colours as rich as possible, but his books are printed on uncoated stock. I will, of course do the initial colour correction in rgb, but once converted, I often need to make further tweaks in the CMYK.

These are always printed offset, as they are printed in the tens or hundreds of thousands and the entire workflow uses a profile supplied by the publisher, determined by the stock used.

The final artwork then goes to the publisher’s production department. They won’t make any further amends, but will check it over for any production issues.

They will then determine which of their printers they use. It is sent to one of a few, who could be in China, Vietnam, or Italy. (A lot is determined by the content, as China refuses to print certain books – for example there can never be mention of Taiwan as a separate state.)

I have no control over this – I’m not going to Shanghai to do a press pass (though I could be persuaded to do a weekend in Bologna!).

Because of this, I need to know, with as small a margin of error as possible, that what I expect to come back, does.

Furthermore, they are always printed with text as an overprinting 5th black, for foreign language Co-Ed’s, so I have to know that when the artwork goes out the door it is correct.

In short, as others have said, it all depends on the job you are doing. The trick is to always ask the printer printing the job how they want it supplied.

1 Like

Yes, that’s another reason why I prefer to make the RGB to CMYK conversions myself on non-digital jobs. I don’t want any surprises.

For example, I might have a nice landscape photo in a prominent spot in a magazine. Once converted to CMYK, I find the beautiful, rich RGB blue sky turns into a dull bluish-grey. Once I know this, I might be able to boost the cyan or increase the saturation or vibrancy of the sky to help mitigate the problem.

1 Like

It may have been mentioned somewhere above that once you convert an image to CMYK (or any other smaller gamut) and save it, all of that RGB color data is lost. You cannot recover it by converting the CMYK image back to RGB.

Also as Joe was pointing out gamuts above, I wanted to point out that sRGB is not not better than CMYK, and in some cases detrimental. See the gamut chart below and how much larger the CMYK gamut is on the blue-green side compared to sRGB. If you can get stock photos in Adobe RGB do it. Avoid sRGB. And if taking your own photos, of course use RAW.

1 Like

Thank you all for your input, it’s much appreciated! All being said, I went ahead and sent a friend an RGB file to print an 8x10 and she printed it through CVS Pharmacy. It was horrific! The white wood had a blue tint and the blue flowers were intensified x10! So I decided to print her a CMYK version at Walgreens. Come to find out they don’t accept CMYK! So I sent them the RGB file and they actually did a nice job with the print. As mentioned it seems to be a hit or miss. Regarding Etsy, someone suggested that I offer both JPG RGB and PDF CMYK versions of the artwork so they can pick and choose. Sounds like a lot of work, but I don’t want to risk them getting a bad print (although it sounds like that’s on the printer they go with.) Thanks again everyone!