RGB to CMYK conversion?

[Nod]

How necessary is this for graphics (not too colour sensitive) rather than photos?

Mrs Nod has been asked to supply a CMYK rather than RGB to the printer but a quick bit of research suggests that this is no longer that necessary. Typically, it's past going home time for the printer, hence me asking here! If it makes any difference, they've asked for a PDF rather than any other format.

TIA for any advice.

 

[dcash29]

They most probably want the file in CMYK so it saves them time by not having to convert it. They ask for PDF so everything is embedded within the file.

 

[Nod]

Thanks for the reply, Dave.

Just read the instructions she wrote down and spotted the "IDEALLY as CMYK", so hopefully the sRGB PDF will do. It's an 800mm x 2000mm banner so not going to be cheap, hence me not wanting to screw it up for her! I'll speak to the printer on Monday just to make sure the sRGB will be OK.

 

[Kodiak Qc]

•
CMYK vs RGB
1• RGB is a light additive colour space as CMYK is light subtractive.
2• Screens are additive RGB and prints are subtractive CMYK.

I would not lose my time sending RGB photos or layouts to my printer because…
well, he knows I know better. Specially in colour space conversion, as photographer,
I know that things may go wrong and I absolutely want to have total control on my
pictures, in every aspect.

I you trust a printer to do that for you… you may be in for a ride!

PDF vs any other format.
The great advantage of the PDF format is that, as industry standard, it make everything
easier between the printer and you, say it is like an interpreter! I has, imbedded all the
info about colour space, transparency colour scales and grey tones etc

So, the requirements are professional and reasonable.

 

[Nod]

As I said in the original post, the banner isn't critically colour sensitive - no photos, just a logo. IF I could find an easy way to convert the sRGB PDF to a CMYK in PSE 12, I would have done it already but using the help button suggested that the conversion wasn't necessary. The printer knows what the logo looks like in the "correct" colours so should be able to get a decent enough match for Mrs Nod's needs.

 

[dave_bass5]

I expect tihs si all done and dusted but thought i'd chime in
If you have Acrobat pro you can do the conversion in that. I work for a printers and we normally ask for a CMYK file, but as others have said, the printers RIP will do the conversion so its not really necessary.
The reason we ask for a CMYK file is it will look closer to the print on the clients screen. Not the same of course, but any bright/neon etc colours will be changed before they send the file in, so they can judge this and wont get any big surprises when their Office documents come out looking dull ;-). Most of our clients are designers so they work in CYMK anyway.
With Digital printing the best generic colour profile to use is probably FOGRA39. You should be able to choose this conversion when making a PDF from most applications, although im not sure if you need Acrobat pro also installed.

 

[retrosi]

I work in a large format printers.
If it's not colour critical then it won't matter to you!
However, we have had some srgb & argb files which we printed and they came out way different.
If the printer is a cmyk printer it will print anything it is sent but it should really be in cmyk.
It just may not look as intended.
The printers used are not rgb home printers and expect cmyk.
The printers we use have 5 meter wide media & 1.5 gallon ink tanks.
The conversion is easy enough and shouldn't really cost extra.
The reason companies ask for this is if it's done in house and then looks wrong the customer complains.
We on the shop floor have complained to the sales staff for years now to grow a set and tell the customers what is what.