Will most printing houses convert my RGB file into CMYK? [SOLVED]

iggy · **Posted:** Sat Jul 16, 2016 12:43 pm **(#1)**

GIMP Version: 2.8.14
Operating System: Linux
OS Version: Xubuntu
GIMP Experience: New User

I'm going to be making paperback covers from my ebook covers. My ebook covers are jpgs (which are RGB) and the printers want CMYK. So I was checking out plugins for GIMP to make the conversion, but then I read somewhere that most printers know how to make the conversions and I don't need to worry about doing it myself. True?

Wallace · **Posted:** Sat Jul 16, 2016 4:02 pm **(#2)**

iggy wrote:

GIMP Version: 2.8.14
Operating System: Linux
OS Version: Xubuntu
GIMP Experience: New User

I'm going to be making paperback covers from my ebook covers.
My ebook covers are jpgs (which are RGB) and the printers want CMYK.
So I was checking out plugins for GIMP to make the conversion,
but then I read somewhere that most printers know how to make the conversions and I don't need to worry about doing it myself.
True?

Totally depends on the print house.
Each print bureau have their own standards e.g. transparency flattened, pdf below 1.4 version etc.
I wouldn't count on the print house for file conversion.
The printer may convert it for you,
then you'll have no control on the final result.
Sometimes it gives OK results,
sometimes horrible.

Here's something to consider...

PDF, EPS, TIFF or native application files (.ai, .psd, .indd).

If they are strictly photos... .tiff or .psd

For Indesign (INDD) files, .pdf

For Illustrator .ai or .eps or .pdf, but in some cases .tiff works better.

iggy · **Posted:** Sat Jul 16, 2016 6:36 pm **(#3)**

Wallace wrote:

iggy wrote:

GIMP Version: 2.8.14
Operating System: Linux
OS Version: Xubuntu
GIMP Experience: New User

I'm going to be making paperback covers from my ebook covers.
My ebook covers are jpgs (which are RGB) and the printers want CMYK.
So I was checking out plugins for GIMP to make the conversion,
but then I read somewhere that most printers know how to make the conversions and I don't need to worry about doing it myself.
True?

Totally depends on the print house.
Each print bureau have their own standards e.g. transparency flattened, pdf below 1.4 version etc.
I wouldn't count on the print house for file conversion.
The printer may convert it for you,
then you'll have no control on the final result.
Sometimes it gives OK results,
sometimes horrible.

Here's something to consider...

PDF, EPS, TIFF or native application files (.ai, .psd, .indd).

If they are strictly photos... .tiff or .psd

For Indesign (INDD) files, .pdf

For Illustrator .ai or .eps or .pdf, but in some cases .tiff works better.

Thanks Wallace. But what did you mean by 'Here's something to consider..."? What am considering (about the PDF etc. that follows)?

Wallace · **Posted:** Sat Jul 16, 2016 8:02 pm **(#4)**

iggy wrote:

Thanks Wallace.
But what did you mean by
'Here's something to consider..."?
What am considering (about the PDF etc. that follows)?

If you image is a photo, go with (tiff or .psd).

Native application files which your printer might except.

For Indesign applications use (.pdf)

For Adobe Illustrator and any other Adobe applications, which include .eps files, .tiff may works better.

rich2005 · **Joined:** Mar 04, 2011 **Posts:** 2615

Quote:

I'm going to be making paperback covers from my ebook covers. My ebook covers are jpgs (which are RGB) and the printers want CMYK. So I was checking out plugins for GIMP to make the conversion, but then I read somewhere that most printers know how to make the conversions and I don't need to worry about doing it myself. True?

Not True.

While commercial printers are becoming a little more flexible there will be in the small print something like this.

Files submitted in RGB or Pantone color mode will be converted automatically to CMYK.
Converting these to CMYK would cause a shift since they are not of the same color spectrum.

A disclaimer that if you do not like the conversion, tough, you should have used CMYK

Using xubuntu, the plugin separate+ is (along with lots more) in the package gimp-plugin-registry.
or
online conversion http://www.rgb2cmyk.org max file size 12 MB

Odinbc · **Posted:** Sun Jul 17, 2016 9:15 am **(#6)**

déjà vu
Does 72 DPI vs. 300 DPI make a big difference for ebook covers?
Is GIMP as good as Photoshop for making ebook covers?

I'm not sure if this one was mentioned already, e-Book Cover File Size Specifications from The Book Designer.

iggy · **Posted:** Sun Jul 17, 2016 2:24 pm **(#7)**

Wallace wrote:

iggy wrote:

Thanks Wallace.
But what did you mean by
'Here's something to consider..."?
What am considering (about the PDF etc. that follows)?

If you image is a photo, go with (tiff or .psd).

Native application files which your printer might except.

For Indesign applications use (.pdf)

For Adobe Illustrator and any other Adobe applications, which include .eps files, .tiff may works better.

Thanks Wallace.

iggy · **Posted:** Sun Jul 17, 2016 2:29 pm **(#8)**

Odinbc wrote:

déjà vu
Does 72 DPI vs. 300 DPI make a big difference for ebook covers?
Is GIMP as good as Photoshop for making ebook covers?

I'm not sure if this one was mentioned already, e-Book Cover File Size Specifications from The Book Designer.

True enough, Odinbc,

but this one was more about what the printing house would do (which I didn't ask in my other posts).

iggy · **Posted:** Sun Jul 17, 2016 2:38 pm **(#9)**

rich2005 wrote:

Quote:

I'm going to be making paperback covers from my ebook covers. My ebook covers are jpgs (which are RGB) and the printers want CMYK. So I was checking out plugins for GIMP to make the conversion, but then I read somewhere that most printers know how to make the conversions and I don't need to worry about doing it myself. True?

Not True.

While commercial printers are becoming a little more flexible there will be in the small print something like this.

Files submitted in RGB or Pantone color mode will be converted automatically to CMYK.
Converting these to CMYK would cause a shift since they are not of the same color spectrum.

A disclaimer that if you do not like the conversion, tough, you should have used CMYK

Using xubuntu, the plugin separate+ is (along with lots more) in the package gimp-plugin-registry.
or
online conversion http://www.rgb2cmyk.org max file size 12 MB

Thanks Rich. That's good to know. I will definitely do the conversion before submitting to Createspace. Interestingly, I'd already bookmarked that online conversion link. So that works pretty well? (That would make things awfully easy for a troglodyte like me.)

And if I have to get the plugin (I went to the plugin site here and couldln't find it) where do I find that? (Could you give me a link?)

Thanks very much. (And good to see you!

)

rich2005 · **Joined:** Mar 04, 2011 **Posts:** 2615

Quote:

..Thanks Rich. That's good to know. I will definitely do the conversion before submitting..

Only so that any change in colour does not come as a surprise.

Does http://www.rgb2cmyk.org work?

It does the job but try and find out the particular .icc profile the printer wants you to use.

Where is gimp-plugin-registry? Not in "I went to the plugin site here and couldln't find it" that is for sure. It is in the 'buntu software repository.

From memory xubuntu comes with Synaptic. Use that. Looks like this

Attachment:

synaptic.jpg [ 48.84 KiB | Viewed 3912 times ]

Otherwise you can use command line in a terminal

Code: Select all

sudo apt-get update
sudo apt-get install gimp-plugin-registry

Note: It is a big collection of plugins/scripts, some useful, some not.

A computer troglodyte? Save this for a rainy day in your cave.
A look at how Gimp is organised in linux. http://youtu.be/U02lm64tnCQ

iggy · **Posted:** Mon Jul 18, 2016 2:51 pm **(#11)**

rich2005 wrote:

Where is gimp-plugin-registry? Not in "I went to the plugin site here and couldln't find it" that is for sure.

Ha ha. Thanks for the laugh!

rich2005 wrote:

It is in the 'buntu software repository.

From memory xubuntu comes with Synaptic. Use that. Looks like this

Attachment:

The attachment synaptic.jpg is no longer available

Otherwise you can use command line in a terminal

Code: Select all

sudo apt-get update
sudo apt-get install gimp-plugin-registry

Note: It is a big collection of plugins/scripts, some useful, some not.

A computer troglodyte? Save this for a rainy day in your cave.
A look at how Gimp is organised in linux. http://youtu.be/U02lm64tnCQ

I went to synaptic. It gave me this whiney window (see attachment) but when I went to GIMP I had all kinds of new stuff (FX foundry, Script Kung-Fu etc.) so I'm assuming I have it.

So what are the good plug-ins in this bunch for making ebook covers?

P.S. I like my cave. (Except for the bats.)