Plate Curves

[zacgil]

So, we are starting to have some color issues on press, not being able to match proofs, especially matching Reds.  We recently re-calibrated our proofers and in my opinion, it helped expose a problem that has been getting worse over time.  However, some seem to think that making our proofs color accurate, is the root of our issues....Anyways, we are not currently using any Plate Curves, just Press Curves.  And they are being applied by Prinergy 5.1.  So I would like to create some simple Plate Curves.

At the bottom of every plate is a simple QC strip with a 2%, 25%, 50%, 75%, and 98% swatch.  It is my understanding that if I remove the Press Curve, output some plates, I should get at 2%,....,98% dot percentage reading aka they match the QC strip.  

So my next move would be to go into Harmony and enter my readings into the current section, linearize my target, and create a calibrated curve.  

While this seems simple enough, I just want to make sure I'm not forgetting anything or if I need to make sure to factor in other variables.  My initial concern is that the Press Curves already compensate for the lack of a Plate Curve, and therefore adding a Plate Curve would just dig us a deeper hole.  

Anyways, I'm sure not all of this makes complete sense, so feel free to have me clarify...

[DigitalCrapShoveler]

Press curves? What exactly would that be if not a curve being applied on output? Where did these curves originate and what exactly are they doing? Are you sure your plates are linearized without any curves? That's where I would start.

You can't apply curves to anything until you get a straight linear sheet printed off press as neutral as possible. When you get that, you can start applying curves to make up or compensate for what is lacking or gaining. Your proofs will be calibrated after getting a good press sheet that you can scan from using a spectrophotometer.

There's a lot more to this...

[Farabomb]

 

No really, I need to understand this. I was under the impression you make the plate produce a dot that matches what's seen on screen. A 50% on screen is what you get on the press sheet. The boss is under the impression that we should be matching film and the gain of days past.

[zacgil]

Press Curves = Print Curves, at least in Prinergy.  It seems to me that the Plate Curves are what is suppose to linearize the plate.  It makes up for anything that the Imagesetter, processor, chemistry, might do to the plate.  The Press/Print Curve is what compensates for Dot Gain on the press.  So what I'm really asking is, how do I linearize my plates? 

The press was fingerprinted about 3 or 4 years ago, and that is when we got our Press/Print Curves.  However, I think this was done without ever linearizing the plates.  Which seems a little backwards to me.

[DigitalCrapShoveler]

No really, I need to understand this. I was under the impression you make the plate produce a dot that matches what's seen on screen. A 50% on screen is what you get on the press sheet. The boss is under the impression that we should be matching film and the gain of days past.

Yes, this is true, and done with curves. The press curves or just curves, are what you use to compensate for what you get on press. To start you have to make sure your plates are linearized. You HAVE to calibrate your plates first to make sure you are starting off on an even keel. If your plates aren't neutral right off the bat, you will play hell trying to match anything.

Once you achieve true linearization, you can then start tearing apart your proofers and applying curves to match your output on press. You have to start with a press sheet ran straight linear. Then you can figure out where your dot is falling off, or being saturated. It's a lot easier to do with a spectrophotometer to read the colors and apply values to your curves numerically. Doing it by sight is just asking for trouble.

[Joe]

Lets start from the beginning. Output a plate with the scale with no curve applied. (Plate Curve or Print Curve). This will tell you if your plate is linear which it probably isn't so in Harmony you would create a Plate Curve to make it linear...a 2% = a 2% up through the 98% and a solid. Once you have a linear plate than you can create a Print Curve to adjust for dot gain etc...we make our 50% read a 38% for newsprint. About a 44% for coated.

[DigitalCrapShoveler]

Lets start from the beginning. Output a plate with the scale with no curve applied. (Plate Curve or Print Curve). This will tell you if your plate is linear which it probably isn't so in Harmony you would create a Plate Curve to make it linear...a 2% = a 2% up through the 98% and a solid. Once you have a linear plate than you can create a Print Curve to adjust for dot gain etc...we make our 50% read a 38% for newsprint. About a 44% for coated.

Joe beat me to it.

[Joe]

Lets start from the beginning. Output a plate with the scale with no curve applied. (Plate Curve or Print Curve). This will tell you if your plate is linear which it probably isn't so in Harmony you would create a Plate Curve to make it linear...a 2% = a 2% up through the 98% and a solid. Once you have a linear plate than you can create a Print Curve to adjust for dot gain etc...we make our 50% read a 38% for newsprint. About a 44% for coated.

Joe beat me to it.

Actually you got in just ahead of me. I hate when that happens!

[DigitalCrapShoveler]

Lets start from the beginning. Output a plate with the scale with no curve applied. (Plate Curve or Print Curve). This will tell you if your plate is linear which it probably isn't so in Harmony you would create a Plate Curve to make it linear...a 2% = a 2% up through the 98% and a solid. Once you have a linear plate than you can create a Print Curve to adjust for dot gain etc...we make our 50% read a 38% for newsprint. About a 44% for coated.

Joe beat me to it.

Actually you got in just ahead of me. I hate when that happens!

Whatever... as long as we get these people fixed, right?

[Joe]

Lets start from the beginning. Output a plate with the scale with no curve applied. (Plate Curve or Print Curve). This will tell you if your plate is linear which it probably isn't so in Harmony you would create a Plate Curve to make it linear...a 2% = a 2% up through the 98% and a solid. Once you have a linear plate than you can create a Print Curve to adjust for dot gain etc...we make our 50% read a 38% for newsprint. About a 44% for coated.

Joe beat me to it.

Actually you got in just ahead of me. I hate when that happens!

Whatever... as long as we get these people fixed, right?

Yes Ear. That is right.

[DigitalCrapShoveler]

Press Curves = Print Curves, at least in Prinergy.  It seems to me that the Plate Curves are what is suppose to linearize the plate.  It makes up for anything that the Imagesetter, processor, chemistry, might do to the plate.  The Press/Print Curve is what compensates for Dot Gain on the press.  So what I'm really asking is, how do I linearize my plates? 

The press was fingerprinted about 3 or 4 years ago, and that is when we got our Press/Print Curves.  However, I think this was done without ever linearizing the plates.  Which seems a little backwards to me.

It is very backwards and seems to me that it more compounds the problem more than fixing it. It also makes it very difficult to chase down color problems. Of course when a fingerprint specialist comes in, they more or less figure you are already calibrated to begin with. Their job is to match color on all output devices, not do menial chores that Prepress should already have locked down.

[DigitalCrapShoveler]

Lets start from the beginning. Output a plate with the scale with no curve applied. (Plate Curve or Print Curve). This will tell you if your plate is linear which it probably isn't so in Harmony you would create a Plate Curve to make it linear...a 2% = a 2% up through the 98% and a solid. Once you have a linear plate than you can create a Print Curve to adjust for dot gain etc...we make our 50% read a 38% for newsprint. About a 44% for coated.

Joe beat me to it.

Actually you got in just ahead of me. I hate when that happens!

Whatever... as long as we get these people fixed, right?

Yes Ear. That is right.

I never get tired of hearing that.

[Farabomb]

That's what I was thinking. You have to cut on the plate to account for gain on press. You make all the values 2%-98% read that on the sheet at normal running densities with your house stock, chemical, ink... what you normally use day to day. The designer is expecting a 50% to be a 50% and designs accordingly.

After you have the plate curve set to produce this you make a profile for the proofer to chase what the press delivers with the linear plate. If everything is producing the values correctly you have a target to hit.

This will be a hard sell to the powers that be here. He still thinks we should be matching film and press gain. He thinks that it produces richer, fuller printing. That may be true but designers don't consider that anymore (if they ever did). They expect that their 50% will be 50% and so on.

[DigitalCrapShoveler]

That's what I was thinking. You have to cut on the plate to account for gain on press. You make all the values 2%-98% read that on the sheet at normal running densities with your house stock, chemical, ink... what you normally use day to day. The designer is expecting a 50% to be a 50% and designs accordingly.

After you have the plate curve set to produce this you make a profile for the proofer to chase what the press delivers with the linear plate. If everything is producing the values correctly you have a target to hit.

This will be a hard sell to the powers that be here. He still thinks we should be matching film and press gain. He thinks that it produces richer, fuller printing. That may be true but designers don't consider that anymore (if they ever did). They expect that their 50% will be 50% and so on.

You can tell your boss, DCS thinks he's a moron and should leave the big-boy work to the adults.

Film curves were created to compensate for the many generation losses you achieved though using a vacuum frame and transferring a dot to plate via light exposure. Now that there's this new invention called CTP, those curves are absolutely archaic and worthless.

[Farabomb]

I'm aware of this, I just have to figure out how I can tell him so that he thinks it's his idea. That's the only way it will get done.