Are free icc profiles trustworthy?

[texshooter]

What good is an icc paper profile that you download from the Internet unless the profiler used my exact monitor and printer?  How is it possible to profile, say, Ilford Gold Silk on an Epson 3800 that will work on anybody's monitor.  I plan to purchase paper sample packs from many brands and I don't know if I should trust pre made icc profiles, or should I make my own using my color munki.

[Farmer]

The profiles don't describe your monitor, they describe the media and the printer combination.  Your monitor will be profiled by you.  Colour aware software will deal with the translation from one to the other in order to allow you to do things like soft proofing.

The profiles describe colour as it pertains to the combination to which they relate.  A media profile to media and printer with specified driver and printer settings.  A monitor profile to monitor and GPU and OS and driver.  And so on.

A custom profile done on your specific printer may improve on a generic or canned profile, but a lot of it comes down to your expertise in creating profiles compared to that of the vendors/manufacturers.  For your 3800, you will likely find a vendor profile for your Ilford media will be very good and quite likely at least as good as that which you could initially create with your Color Munki.

[texshooter]

Ya but the vendor did not profile the Ilford Gold paper by sending a color chart directly from the camera or hard disk to the Epson 3800 printer. The vendor first looked at the color chart on his monitor to make sure the colors looked right, then he sent the chart image from PS to the printer.  In other words, the vendor's monitor is inseparable from the paper icc profile process.  What happens if my monitor has a different contrast ratio or color cast than the vendor's?  I'm doomed unless I can get my monitor's output identical to the vendor's monitor, which is impossible.  What he sees is what he gets, but what I see is not what he gets.  I can always recalibrate my monitor using a color munki, but that won't get my monitor to match with his.  Or will it? It just seems to me that vendor paper/printer  icc profiles will be reliable only if I can first be made to see exactly what the vendor sees on his monitor. And short of using the same monitor as his and calibrating it using the same spectrophotometer has his, I don't see how uniformity is a sure thing. Unless it's all close enough for government work.

[Farmer]

No, the vendor did NOT look at a colour chart on a monitor in order to make sure the colours looked right.  They used spectrophotometers to measure the colour accurately.

The vendor's monitor has absolutely nothing at all to do with creating a printer a profile, just as your monitor has absolutely nothing at all to do with the process of creating a printer profile.

You are misunderstanding the process.  The spectro measures colour on the media and from that creates a printer profile.  A seperate task measures colour on your monitor to create a profile for that.  If you want to, you can create custom profiles for your camera as well where the colour captured by the camera is measured and a profile created from that.

In each step, you are describing the colour associated with a single thing: monitor or printer or camera and none of them rely on the other.  Once you have a profile for each, you have a method by which to translate from one thing to another because they are all described in a common manner (the colour spaces).

[texshooter]

Then if everybody is profiling their cameras, monitors and printers separately and with a diverse number of spectro devices, then there must be an international standard by which all these calibration devices must conform to. Or is there more than one standard? Maybe I should dig up the spec sheet on my color munki to see what standard it uses and try to find out if it is the same as the vendor's spectro standard. Ill look into it.

[francois]

You should really purchase Michael's L-L Guide to Colour Management. It's just $16!

http://www.luminous-landscape.com/videos/tutorials/guide_to_colour_management.shtml

If you're in a hurry then, here's an [old] article:
http://www.luminous-landscape.com/tutorials/understanding-series/und-print-mgmt.shtml

[Tony Jay]

All the replies to the original question are correct.
However, here is a situation that will put a few things in perspective:
   Were I to send you and a friend the same picture file and if both of you were
   using the same printer/paper combination as well as the same ICC profile for that
   paper/printer combination then if both of you were to print that file without any editing whatsoever using the same
   printer setup then the resulting prints should be indistinguishable.

In this situation the monitor, and how it is profiled, as well as the rest of the computer hardware, is completely
irrelevent in how the print will look. The ICC profile for the printer/paper combination should guarantee a consistent print.

Once editing comes into the picture, so to speak, then how your monitor is profiled becomes very important since that determines
the apparent tone and colour of the picture file as you see it. If your monitor is badly profiled then it is very likely that, even with soft proofing,
that what you see on your screen will not look at all like the print. This will be true whatever ICC profile (canned versus your spectrophotometrically generated profile) for that printer/paper combination you are using.

Colour management is not insurmountable so your current confusion will not last if you apply yourself to understanding it.
The LuLa site as well as this particular forum has multiple brilliant explanations covering these issues and much more.
Many contributors to the forums are world authorities on colour mangement and some are authors of books that approach biblical status
concerning  colour management - Schewe and Andrew Rodney spring to mind.

So start reading or watching the resources readily avalable on this site and then pose some more better thought out questions that the true expert
contributors can sink their teeth into and so really help you along.

cheers
Tony Jay

[ErikKaffehr]

Hi,

Monitor is not involved in profiling paper at all. Technically, you could produce a profile entirely without using any monitor.

Best regards
Erik

Ya but the vendor did not profile the Ilford Gold paper by sending a color chart directly from the camera or hard disk to the Epson 3800 printer. The vendor first looked at the color chart on his monitor to make sure the colors looked right, then he sent the chart image from PS to the printer.  In other words, the vendor's monitor is inseparable from the paper icc profile process.  What happens if my monitor has a different contrast ratio or color cast than the vendor's?  I'm doomed unless I can get my monitor's output identical to the vendor's monitor, which is impossible.  What he sees is what he gets, but what I see is not what he gets.  I can always recalibrate my monitor using a color munki, but that won't get my monitor to match with his.  Or will it? It just seems to me that vendor paper/printer  icc profiles will be reliable only if I can first be made to see exactly what the vendor sees on his monitor. And short of using the same monitor as his and calibrating it using the same spectrophotometer has his, I don't see how uniformity is a sure thing. Unless it's all close enough for government work.

[texshooter]

I decided it would be overkill to create my own Color Munki ICC profiles for the 30+ papers I plan to test, because I"m only interested, at this point, in finding which papers I like the most. I don't think the print has to match 100% with my monitor just to find the answer to this question, nor do the vendor ICC profiles need to be scientifically accurate.

However, once I've found my favorite papers, then I will create my own ICC profiles and use them post hoc.

[Alan Goldhammer]

I decided it would be overkill to create my own Color Munki ICC profiles for the 30+ papers I plan to test, because I"m only interested, at this point, in finding which papers I like the most. I don't think the print has to match 100% with my monitor just to find the answer to this question, nor do the vendor ICC profiles need to be scientifically accurate.

However, once I've found my favorite papers, then I will create my own ICC profiles and use them post hoc.

You are risking a lot of frustration if you don't set up a proper color managed workflow from the outset.  You also should use one of any number of available standard prints to evaluate papers along with a couple of favorite prints of your own.  This standard print is quite good and a demanding one to gauge the worthiness of any paper.  You will also need to use it for profile evaluation to make sure that the colors are truly reproduced.  As with the suggestion of others you should watch the LuLa color management video (or better yet get the whole 'From Camera to Print' series) since from some of your previous comments in this thread it's not clear that you have a firm grasp of the fundamentals.

[Farmer]

Vendor profiles, such as from Epson, are very much "scientifically" accurate. They use more advanced hardware and techniques and/or 3rd party CM experts.