composite cmyk vs composite leave unchanged

V

Visualaid

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So I had this terrible rgb low res. file from customer and it needed to print 4 color.
I converted the file to CMYK, sent to rip as composite leave unchanged (because the rip tells it to separate) from indesign to preserve the colors of the original artwork. It came out dull and crappy of course.
So they had me send it Composite CMYK the next time and it seemed to have brighter colors when looking at it in roam.
So the pressman swear it's my fault, but I tested another 4 color job, sending as both composite leave unchanged and composite cmyk , both looked exactly alike, looked great. This was better artwork, vector art- versus the first terrible file that was originally rgb and then converted to cmyk.

anyone shed some light on this? I am tired of being blamed for everything that goes wrong back there. could it be that the one file was crappy, and the next file was great.
composite cmyk vs composite leave unchanged...
thanks:mad:
 
Well the difference is called colour management. Depending on how you configure your workflow a job may have properties that make it look the same wether you send it composite CMYK or composite unchanged.

Read the posts on colour management and see if you begin to understand the problem.
May as well ask why the food you put in the microwave 1 minute sometimes is deliceous and sometimes will be frozen to the core. The result you get out depends on what you put in, and some things may seem to work.
 
Lukas is right (as usual), the answer is color management...but more specifically, it sounds to me like the RIP for your press may not have been set up with proper color management--at least when it comes to RGB colors. It's really hard to say without more info, such as whether the RGB file had an embedded profile or not. If it did, one possibility is that the RIP is not be set to honor embedded profiles, but your InDesign settings are. If the file didn't have an embedded profile, then the difference might only be which profile is set as the default for untagged images (on RIP vs in your InDesign settings). There are tons of other possibilities, but that might give you a good place to start. Good luck!
 
yes

yes

Lukas is right (as usual), the answer is color management...but more specifically, it sounds to me like the RIP for your press may not have been set up with proper color management--at least when it comes to RGB colors. It's really hard to say without more info, such as whether the RGB file had an embedded profile or not. If it did, one possibility is that the RIP is not be set to honor embedded profiles, but your InDesign settings are. If the file didn't have an embedded profile, then the difference might only be which profile is set as the default for untagged images (on RIP vs in your InDesign settings). There are tons of other possibilities, but that might give you a good place to start. Good luck!
That sounds like what I was thinking. It was a flyer built in rgb. I simply rerasterized and resized, saving as cmyk 400 res. and placed in indesign template. So how do I check a flattened rgb file for embedded profiles? untagged images? Looks like I've got some research to do. Can anyone suggest books to read or is this just no brainer stuff? I have never had any trouble in the past with color management. It seems to me it depends on what rip software each company runs, in my past experience I've never had to worry about untagged images, rgb files being converted to cmyk then printing horribly. I believe our harlequin rip is like version 6.

thank you again guys for all the responses and help. have a great day:)
 
There is alot of good books, as well as lotts of information on the web. I have "Digital Color Management" by Jan-Peter Homann. (ISBN 978-3-540-67119-0) but there are many more "Realworld colour management" is a popular one.
 
Still curious

Still curious

I'm still curious as to the difference between sending something from InDesign as composite cmyk vs composite leave unchanged. What really is the difference?
 
I'm still curious as to the difference between sending something from InDesign as composite cmyk vs composite leave unchanged. What really is the difference?

I ended up finding somewhere that composite CMYK is the way to go. leave unchanged basically preserves the documents original color. composite CMYK is like telling it you are printing it to a CMYK printer, which doesn't make sense to me because RIP software is not a cmyk printer.

so the RGB file I started out with ended up printing really bad and dull because I sent it leave unchanged. we tried same file as composite CMYK and the colors were much brighter and a better finished product.
 
Or in really simple terms, Adobe does a better job at RGB conversion than whatever your RIP is. I found this out with gray scale items. We print on all digital equipment, no presses DI or plate. When doing a color and b&w version of the same flyer we might use the same layout but send it again in "composite gray." (Yes I know how I should do it). If we use one layout and turn it gray at the RIP it looks terrible, very gained in the shadows and washed out in the highlight. It's a Creo RIP, Adobe just does better. You have found it with color.
 
Color Management Books

Color Management Books

There is alot of good books, as well as lotts of information on the web. I have "Digital Color Management" by Jan-Peter Homann. (ISBN 978-3-540-67119-0) but there are many more "Realworld colour management" is a popular one.

These are the two books on my desk and I swear by them.
 
@Visualaid I find your post contradictory.

Also I am a little unsure what manu you are refering to.
To leave colours unchanged is to choose not to manage colour it means you have no control.

Composite CMYK means to convert to CMYK, the current application settings are used, if this is a good idea depends on your sources being tagged right and your settings being appropriate. Can sometimes yeild identical results. Big difference is that the resulting file will be more or less predictable. Colour conversions are nailed down and all future colour conversions will be with the new values at base.
Have the settings been bad you still are now able to tell and measure that because you now have a lower level of abstraction. The file will image and view more consistently irrespective of device from that point on.

There is also another term called CMYK (preserve numbers) wich you find in joboptions. This means that non CMYK objects are colour managed, but CMYK objects the numbers are relayed rather than converted. This is also known as safe CMYK. CMYK is device independant, however there are more risks involved in involuntary conversion of CMYK than there is in letting CMYK vary with the exception of photographic style images. This is one of the main reasons why RGB for colour managed data and CMYK for mailed down number art is a common and well proven strategy.
 
?

?

@Visualaid I find your post contradictory.

Also I am a little unsure what manu you are refering to.
To leave colours unchanged is to choose not to manage colour it means you have no control.

Composite CMYK means to convert to CMYK, the current application settings are used, if this is a good idea depends on your sources being tagged right and your settings being appropriate. Can sometimes yeild identical results. Big difference is that the resulting file will be more or less predictable. Colour conversions are nailed down and all future colour conversions will be with the new values at base.
Have the settings been bad you still are now able to tell and measure that because you now have a lower level of abstraction. The file will image and view more consistently irrespective of device from that point on.

There is also another term called CMYK (preserve numbers) wich you find in joboptions. This means that non CMYK objects are colour managed, but CMYK objects the numbers are relayed rather than converted. This is also known as safe CMYK. CMYK is device independant, however there are more risks involved in involuntary conversion of CMYK than there is in letting CMYK vary with the exception of photographic style images. This is one of the main reasons why RGB for colour managed data and CMYK for mailed down number art is a common and well proven strategy.

Ok peeps, if we go back and read my original post, I think we can see we are making a mountain out of a mole hill or whatever they say. Basically, I started with a bad RGB rasterized file, it was a .jpg. I opened in photoshop, converted to CMYK and saved as .tif. Placed that .tif into indesign template and sent to RIP , composite leave unchanged - that printed terribly. Then sent as composite CMYK, that printed colors brighter and overall a better looking end product.
 
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