Rendering for Print?

[tarontis]

Hi everyone,

I have a question I've been trying to figure out for a while now in regards to professionally printing renders.

Obviously Max always outputs renders to an RGB colour format and there is no way to change this except to convert the image to CMYK afterwards in post. Even doing this though I never seem to get the colours that I am trying to achieve.

I have experimented with ICC colour profiles to compensate for our printers settings, and have also recently tried an Eye-one Display 2 Monitor calibrating tool to see if this helps, but nothing seems to get very close and I find myself having to almost delibratly make my images look awful in photoshop before printing, or they will come out too dark, or mismatched colours... etc.

Obviously this then double the workload as I have to have renders in RGB to send to a client by email which look good, and a second set to do large prints for mounting boards, which even then tend to look a fair bit different.

I was hoping someone who works a lot with professional print from Vray would have some insight into this, perhaps give me a walk-through of your work flow?

Thanks
Dan

[add101]

I have also run into this problem and haven't really found a solution.
One thing i have noticed is prints from photographic labs (kodak etc.) are a lot more consistent in colour than printing on paper or card at a normal print bureau where laser printers are used. I'm not sure how colour consistent litho printers are?

I just have my monitors visually calibrated at the moment, but definitely looking into getting them hardware calibrated. Not quite where i want them to be, but a lot closer to prints than before visual calibration!

[tarontis]

Yes the printers we have in the office are laser printers and they do look very different from the images we get back on mounted boards when we send them to a professional printer to manage. However even these tend to be a fair bit different to what you view on the screen...

I haven't made my mind up yet as to whether the calibaration device was worth the money, doesn't seem to have helped much, perhaps I am using it wrong, I'll have to experiment a bit more.

Thats a good idea about using a photographic printer, I'll have to give that a test and see if they give a better result to what I've gotten so far

[Dariusz Makowski (Dadal)]

Heya

em u cant use any eye calibration tool except a proper calibarator... physical one... all u have to do is this

get

Spuder3Elite/Pro (I got elite its great coz u can calibrate 2+ screens to match each other bla bla bla)

U calibraty Printer CMYK or what ever it got to ur photoshop profile basically.

Calibrate scren
Render
Put to photoshop
leave as RGB
Calibrate printer CMYK using Spyder3 to match Photoshop RGB space, No need super professional printers, photoshop will simply pick profile that Spyder3elite created and use it to adjust colors in order to give u exact match on LCD/Photoshop/Max/Print.
Job done. No need to worry etc etc. Just make sure ur clients have calibrated screens... Trust me its a nightmare if they dont...

ah and a tip. Save renders to Tiff 8 bit 300 DPI for low photoshop. For crazy photoshoping go TIF 16bit 300 DPI. About prints if I do job for billboards they usually have 10k+size and printed at 72DPI, if its A2/A3 then 10k+ and 300 DPI... Depends from the size of final image that the client wants...

Enjoy ur prints now


ah and btw if the people that print out ur images have different effect, I believe they will u have to tell them to create profile on their software for u to convert their CMYK color space to RGB just like u did. U cant make max to save to CMYK, so u have to make them go back to RGB... shouldn't be a problem tbh.

[stef.thomas]

I think I'm right in saying that most inkjet printers these days are designed to take RGB images and do the conversion internally. You only really need to convert to CMYK first if your using a more traditional four-colour press. Correct me if I'm wrong.

[Dariusz Makowski (Dadal)]

Yes u are right. But none of those printers are calibrated for professional print. They all are ''calibrated''... but after hardware calibration most of the time u can see the difference in collour. And u do have to check the calibration once a wile... I'm checking mine every month, as well as screens, every 2 weeks.

About printers aren't they all RGB anyway ? and only those 3k+ printers are CMYK...cant remember its been a while since I was in that hardware market...

[mdi]

the problem with CMYK is that no matter how hard you try you will never be able to reproduce the range of colour that RGB has. As someone who works in print, you just have to be aware of what the colours are good and what colours are bad - remembering not to make everything too saturated is always a good start. And at every stage open the files in photoshop and use the "Preview CMYK" option (or just convert it) , if colours are dropping off too much remember to adjust them in the render.

As for printing at home, or even getting the images produced as photographs - These are a totaly different process than 4 colour - So you will probably get much better results printing directly from RGB, but I know next to nothing about that.

[3DMK]

I try to avoid printing at all cost & usually let the print company convert to CMYK as that way I can blame them when it's not right..lol.
If they are a good printer then they should have skills to convert better than us 3d people as they do this EVERY day in their job.

*NOTE
RGB & CMYK are completely different ways to describe 2 completely different forms of light....so in reality they will NEVER match perfectly now...or any time in the future.

RGB is describing ADDITIVE Light- IE. emmited light [such as a monitor] - all colours added equal white
CMYK is describing SUBTRACTIVE Light- IE. reflected light [such as a print] - all colours added equal black

cheers

[freiformgestaltung02]

Hi Dan,
in my design-company, we have often to convert our RGB-renderings to CMYK. We don`t have so much problems with it. Our workflow: rendering with VRAY as TGAs or TIFFs (all in 8bit - more is useless for 4C) - bring it into Photoshop and convert it first to LAB-color (Image - mode- LAB) and then into CMYK (with the direct conversion you will ran into some problems). The next issue is, that you will have to place the pictures in a layout-app like Indesign. There you will have to work in the CMYK-mode (for all colors) and export it into a pdf-file (normally PDF/X1 or PDF/X3) and keep the colors (nor color conversion!!!). So you have a linear workflow...
There may be a slightly difference in the colors, but when you have calibrated your monitors, it may not be too much.
The other workflow we use for smaller displays (Din-A3), is to bring the RGB-pictures to a photo-laboratory and make photos in the size you want to mount on the displays. They were more brilliant than a CMYK-print and you have no problems with the conversion issue...

Greetings
Sascha

[raistlin]

Hi, maybe late but :
There is another reason to have problems with print and conversion, the TAC of the offset used by your printer, call him and ask about this color calibration... I've solved a lot of problem with that... Some technician send their icc CMYK profiles.
Here is some of international profile, very interesting and usefull parameters...
http://www.eci.org/doku.php?id=en:downloads

[tarontis]

Thanks for the replies guys, your comments have been really useful.

I've just been messing around with the monitor calibration software again and I think its looking a lot more accurate this time. Though I have also done an ambient lighting test and the office is far FAR too bright and too warmly lit to display colours correctly, unfortunately nothing I can do about that though, damn these open plan offices!

The thing with Professional printers that I've found is, although yes you can blame them when things don't quite turn out right, at the same time they mostly deal with graphic artists who are working in direct to print programs like Adobe Illustrator, so the image is in CMYK from the start and needs no conversion. SO the ones we use tend to be a bit in the dark when we ask them about converting from RGB.

@freiformgestaltung02

Thanks for sharing your workflow, thats really useful, I haven't had a chance to test it yet but I will try to by the end of the day and see if that provides a better result.

@raistlin

Thats great, thanks for the link, not sure I entirely follow what your saying though, doesn't monitor calibration provide its own ICC profile customised to my display, or are these specially for standardised printers? It still all seems to be a bit of a mine field...


I do wish I could ensure clients have calibrated screens, pretty sure thats never gonna happen though! If only we could just post them each an iPad each and ask them to view it on that! hah!

[jujubee]

Ever since printers have gone well beyond the 4 colors (CMYK) and started adding additional inks/wells, it actually doesn't make sense to convert to CMYK and limit yourself any longer. This also applies to many newer home printers. You have to put a little trust into the hardware that it will interpret the RGB properly. Some printers will say not to even bother. I spoke with some folks over at Epson last year regarding my large format with 8 inks, and they told me just to keep my images RGB in order to remain more accurate.

[AJ Jefferies]

Ever since printers have gone well beyond the 4 colors (CMYK) and started adding additional inks/wells, it actually doesn't make sense to convert to CMYK and limit yourself any longer.

While this may be fine when printing at home or for internal tests, for commercial projects I would strongly advise against this. CMYK is still the defacto process for the majority of print work & while it's fine to add extra inks for a wider gamut on a domestic printer, for commercial repro that would result in a huge hike in material costs.

While, in theory, a good print shop should be able to do their own CMYK separation from an RGB file, it's always good practise to do this yourself. Not only does it give you a good idea of how the image will print, it also gives you a chance to solve some of the problems that might arise (gradient banding/clipping...etc) before you send it off.

[jujubee]

Thats a valid point I'd recommend talking to your printer to see what their recommendations are for the printers they will be using. I think that's probably the safest practice.

[BLADE]

Just my 2 cents from older jobs for printing: If you really want the best print, let the print guy convert the file. He is the one, who has to know his printer, the ink, the paper, the driver ...
Guide him with a good print you have done on your 100 $ office 6 ink printer on glossy photo paper. Thats the only way you can do it. If your client wants to be sure for 100 %, the print guy can do a color proof.

Regards
BLADE