printing on canvas

[Ashwin]

I am a Photographer, many times I require my COLOUR photographs printed on CANVAS., and for that I am required to convert it from sRGB to CMYK.,on many occassion I dont get true colours of the original photographs., and if I want it in Black & White I dont get true Black & white prints on Canvas., although bafter conversion to CMYK my pictures appears to be true Black and white.... as a result my money is wasted

This is always happening., can anybody suggest best way to convert RGB photos toCMYK for printing on CANVAS....?

Any help or guidance will be highly appreciated,

Thanks

Ashwin photographer

[Colin Southern]

Hi Ashwin,

Thanks for posting your question - finally something I can "get my teeth stuck into" today

I print on to canvas for a living (well, one of the things I do for a living anyway), so perhaps I can help.

First question though, "why are you converting to CMYK"? Is this a requirement of whoever does your prints? Although most large format printers use a CMYK inkset (I use an Epson 7800), they none-the-less have an RGB interface.

The other issue is colour-management; essentially there's two things we need to get right here - (1) your monitor needs to be calibrated and profiled, and (2) the whatever printer/canvas combination your using needs to be profiled as well. If you've got those two things sorted then your well on your way.

The other thing that often upsets the apple cart is levels changes being "incorrectly" interpreted as colour shifts (I say "incorrectly" because although you still get the wrong colour, it's because of the brightness change, not a hue shift) (the colour of the sky is a classic for suffering from this; you might think that in a world where they put men on the moon 40 years ago thay'd have married up monitors and printers a bit better, but the bottom line is that one is an additive process and the other a subtractive one - with different gamuts - and we just haven't achieved perfection yet. So - for example - if you choose to have a monitor that's somewhat brighter than normal (even though it's calibrated & profiled) you'll see more shadow detail as a result - so you'll darken things to compensate - and thus many colours will appear more saturated (the brighter you make them, the more they washout).

Perhaps you could have a read of this, and get back to me when your ready so we can delve into this a bit deeper for you. I'd also be interested in seeing a sample image that you think the colours / levels are correct on so we can see if it looks right on our calibrated / profiled screens (just to be sure your not getting what "your asking for" rather than "what you wanted")

[Ashwin]

Thank you COLINS,

As a photographer, most of my work is printed on Photographic colour papers and they come out very acurately.,

Canvas printer only accepts images in CMYK that is why conversion.,

only the problem when I want them on BIG CANVAS,
My True Black & white photos, I dont get correctly., there is sometime greenish., or
blueish tone., as a result same are rejected by my clients., In short if my images are PURE BLACK & WHITE they are spoiled., if in Colour images there are some black and
white portion then it will come out ok.,

before printing on Canvas., I am getting small proof print on paper., after seeing
the proof print on paper., I am trying to re-do the image correction., but still
I am not getting true colours

I do RGB to CMYK conversion in my Photoshop CS3., is there any other better method to do this....?

thanks for the trouble...


ashwin photographer

[kevinbythebeach]

So what do you guys print on canvas? Do you guys think it looks good or just doing it for customers request...Just wondering because I've neevr seen anything that I thought really looked good on canvas..

[Colin Southern]

Thank you COLINS,

Your welcome.

Sounds to me like the printer is introducing colour casts - should be easy enough to verify with a couple of tests.

Some more questions for you though ...

1. Are YOU working from a calibrated and profiled monitor?

2. Has the printer + canvas combination been profiled?

3. Has the printer + paper combination used for the proofs been profiled?

4. Are you soft-proofing on CS3?

5. If you send the printer a greyscale image - to be printed on proofing paper and canvas, does it come back with a cast?

6. What's your knowledge of colour management like? - if you need to get on top of it then the gold standard bar none is "Real World Colour Management by Fraser, Murphy, and Bunting" (2nd edition).

[Colin Southern]

So what do you guys print on canvas?

Everything.

Do you guys think it looks good or just doing it for customers request...Just wondering because I've neevr seen anything that I thought really looked good on canvas..

It's a lot cheaper to produce a ready-to-hang product. Although the canvas is expensive (as is the UV protectant spray), framing costs are actually dirt cheap (I make my own frames and do my own stretching) whereas producing a paper print is dirt cheap, but the framing is the absolute killer ... to the point where I can make a ready-to-hang canvas over 4 times the size of a ready-to-hang paper print, for the same cost.

[Ashwin]

Re: Printing on Canvas

Yes., it is being done., as per requirement of customer

Dear Colin,

My monitor is calibrated as per my Colour Lab's printer.,
as such I am getting my colour prints as I see on my monitor.,

as regards profiling., My Canvas printer does not know anything about this.,
As suggested by you., I will send Solid 50% grayscale file for test printing on canvas.,

One thing I cant understand is that, when my COLOUR IMAGE has any Black & whte image
inside it - it comes out OK it does not contain any cast , anyhow I will be test printing
grayscale image to findout whether there is any colour cast or not

Thanks

[Colin Southern]

My monitor is calibrated as per my Colour Lab's printer.,
as such I am getting my colour prints as I see on my monitor.,

Hi Ashwin,

Sorry, but I'm a bit confused by this. Monitors and Printers need to be profiled to the same standard, but that's done by different pieces of equipment (a colorimeter for the monitor and a spectrophotometer for the printer). If your trying to "calibrate" one against the other, then it's a very "dangerous" game as in essence your trying to offset the errors of one with an opposing error in the other, which ultimately, is a recipe for disaster.

as regards profiling., My Canvas printer does not know anything about this.,

Ah - therein lies 1/2 the problem. Unfortunately, there's just no getting away from it.

As I see it, there's really only 2 choices ...

1. Is to invest in a profiling kit (such as the Spyder III Elite kit) (or one of the competing products such as ColorMunki), or

2. There are various services that can produce a printer profile based on the printer / canvas test targets that you can produce and send in to the service. They're relatively inexpensive - and they should pretty much sort the issue for you once and for all (assuming your monitor is right).

One thing I cant understand is that, when my COLOUR IMAGE has any Black & whte image
inside it - it comes out OK it does not contain any cast , anyhow I will be test printing
grayscale image to findout whether there is any colour cast or not

Yes - it does sound rather strange. What is the printer make / model?

[Ashwin]

Hi Colin,

Thank you for all your technical guidance.,

I am bit unorthodox, I at regular interval include small piece of grayscale image + PICTURE FOR SKIN COLOUR correction in my printing lot ( THIS IS MY TEST STRIPE WITH 20 step change from PURE WHITE TO TOTAL BLACK - )., and thereafter if I find any noticable shift in colour or density of the my test stripe , then I adjust my monitor accordingly., this my make shift arrangement has worked SATISFACTORILY since last 15 years.

As regards colour cast in My BLACK & WHITE Canvas print., I could not solved the problem., anyhow as suggested by you, today I got small grayscaled imaged printed oncanvas and it has comeout OK., This is just because my printer has changed his PRINTER.,

Previously he was using HP 5000., in which this strange thing was happening.,
Now he has purchased HP5100 and it is now OK

Thank you very much for your detailed guidance., thank you once again...

Ashwin

[Ashwin]

Hi Ashwin, perhaps I can help

I'd also be interested in seeing a sample image that you think the colours / levels are correct on so we can see if it looks right on our calibrated / profiled screens (just to be sure your not getting what "your asking for" rather than "what you wanted")

Hi Colin,

Sorry you requested for sample image., I have no sample of my canvas print ,I generally deliver my backup DVD copy to my client after the work has been executed and payment received.
sending herewith my GRAYSCALE STRIPE with photo for adjusting skintone, at regular intervals I
include this stripe in one of my image which I sent for printing from colour lab., if there is any shift
I adjust my monitor accordingly, this may be not right practise., but I get print as I see them on my monitor., as such I am continueing this since last more than 15 years..

Thanks for taking interest in my problem and guiding,

ashwin

[Colin Southern]

Hi Ashwin,

Glad that the problem got sorted

If you have further problems I'd still suggest that both you and your printer make a small investment in some colour management hardware and materials though (to be honest, I really can't understand how any printer could accurately reproduce colour without having a profile made for each paper).

[Ashwin]

Hi Ashwin,

Glad that the problem got sorted

(to be honest, I really can't understand how any printer could accurately reproduce colour without having a profile made for each paper).

Hi colin

I enquired from my Canvas printer and came to know that all the required profiles for various types of canvas and papers and other media are there., and the person who Prints them
makes necessary selection and prints accordingly.,

But he personally has no working knowledge about profiles etc..
Hope matter is now more clear to you

thank you for providing valueable proper guidance in the matter

ashwin

[scrivscouk]

I just read trough your tread and though I would add some tips.

I hope this is helpful as I run a repro house in the UK and produce fine art prints and Scanning.

To give you a quick run down. We can scan a water colour on our drum scanner and print it out on our canon IPF - 90% of the time we do not need to do any colour corrections. The reason for this is simple. High Quality Drum Scanner, High Quality papers and canvas, High Quality Printer, A good expensive RIP, and most important - ICC profiles from start to finish.

So Here is some tips that I hope you find helpful in thr future.

CRT Screens have more depth of colour than LCD

Profile your monitor (After 1 hr its been on)

Have controlled lighting in your room

Monitor Profiling is only "To improve your expectations" (Monitors can't display 100% yellow)

if you use a Lab, ask if you can have a copy of there ICC profile for the printer and substrate they use. This should be an inhouse profile they have created.
Use this profile so you can proof your work - Under proof / simulate colours in PS.

Dont convert to CMYK as this can effect the neutrals when printed via digital printers (Unless you have a good RIP)

Use a hight quality canvas like breathing color or another brand name.

You can see more about us at www.scrivs.co.uk

Cheers Jake

[Colin Southern]

if you use a Lab, ask if you can have a copy of there ICC profile for the printer and substrate they use. This should be an inhouse profile they have created.
Use this profile so you can proof your work - Under proof / simulate colours in PS.

Hi Jake,

Great to meet a fellow printer

Only comment I'd like to make is that in my experience, soft-proofing is only of (extremely) limited value; I find that it does a relatively poor job of simulating canvas black points and also, if you have any colours that are in gamut for the printer (with a CMYK inkset), but out of gamut for the monitor, then soft-proofing still won't show the colour because the monitor is physically incapable of reproducing it. So although I use it, I don't put too much faith in what I see.

[Ashwin]

Hi Scrivscouk

Thank you very much for giving such a good tips and suggestion.,

I was facing this problem since the HP 5000 printer which was used to Print on Canvas
had some trouble., but after this printer was replaced with HP 5100., now I am getting
my work correctly.,

ashwin