Inèdit Software S.L.

neoStampa 6RIP Software with innovative Colormanagement

powered by hueman CMS a Tschudi Technology GmbH development

Color Calibration Tutorial

© 1999 - 2008Copyright by Inèdit Software (neoStampa, ICCPrint) and Tschudi Technology GmbH (hueman CMS)

Calibration Wizard

nèoStampa Calibration is a color calibration wizard for neoStampa 6 to color control your inkjet printer. With Calibra-tion Wizard you can print different kind of test charts in order to control and set ink amount, linearization curves and maximum ink limits. With nèoStampa Calibration Wizard you can also print RGB profiling targets from third-party software, such as MonacoProfiler or Fuji ColourKit in order to create ICC RGB Output profiles for your calibrated Colormanagement workflow.

1.1 Print Configuration

Setup the driver and the printing options that you’d like to calibrate. All of these parameters will be saved into the resulting printing scheme.

Bi-Directional Printing

Connection settings

InksetPrinting settings

Raster settings

Driver

Connection

Connection settings

Select the printer to be calibrated in the drop down bar. If the desired printer is not listed, add a new printer in neoStampa.

Select the connection of the printer (e.g. TCP/IP for Network connected printers, such as Mutoh, Roland, Epson, etc. and FILE for all print-to-file printers, such as Reggiani, Robustelli, Dupont, etc.

Access connection settings with this button to specify the TCP/IP address or the output folder for print-to-file drivers.

Set your color mode in this tab. For original inksets you can select one of the prepared sets. For special or individual inksets you need to select the CMYK + x op-tions, where x specifies the quantity of additional colors including lights and second colors apart from the Cyan, Magenta, Yellow and Black inks.

Enter the inkset button to access and set the inkset order. Set the color order in this tab in correspondance to your printer’s ink set.

Enable nèoHueman Multicolor module to use the hueman CMS engine.

hueman CMS will automatically find the corresponding inkset engine if a logical ink combination has been set. Light colors and second colors will be generated auto-matically.

Color mode

Inkset

Important:

Attention:

Quality

Advanced Printing Settings

Dithering

Raster settings

Some printers internally might not have the same inkset order as you need to con-figure them. See a list with special inksets here.

Set the desired output resolution or output format for print-to-file drivers.

Change printing parameters, such as pass mode, head height, etc. in this button.If you are using print-to-file driver, such as for the Dupont printer, set the output res-olution, the bits per pixel (fix dot = 1, variable dot = 2) and additional save settings.

This example shows how to set up the Dupont ouput settings for 540 dpi printing:

Set the rastering method here. The best quality/performance raster for most ap-plications is “Smooth Estochastic”. This raster is fully compatible with all selectable output resolutions.

If you prefer an AM-raster you can select “Ordered Halftoning” and set the parame-ters in the Raster settings tab, however be aware that the ordered halftoning method does not support variable dot modes.

Note: Special Inksets

Reggiani DReAM

As some printers internally have a predefined inkset it’s necessary to configure the inksets of these specific printers in a different way. Find here a printer that requires special attention:

Following settings are examples of how you need to configure your inkset and ink order in neoStampa in order to have the right colors printed in the correct position:

Printhead 1: BLACKPrinthead 2: BLUEPrinthead 3: CYANPrinthead 4: MAGENTAPrinthead 5: ORANGEPrinthead 6: YELLOW

Printhead 1: BLACKPrinthead 2: GRAYPrinthead 3: CYANPrinthead 4: MAGENTAPrinthead 5: ORANGEPrinthead 6: YELLOW

In the Advanced printing settings button you can select the used Ink type and Com-pression quality but the Ink configuration must ALWAYS be following, eventhough you might be using a Gray or Violett color.

Note: Special Inksets

Mutoh Falcon II / Rockhopper II / Viper / Viper TX / Spitfire

As some printers internally have a predefined inkset it’s necessary to configure the inksets of these specific printers in a different way. Find here a printer that requires special attention:

Following settings are examples of how you need to configure your inkset and ink order in ICCPrint and neoStampa in order to have the right colors printed in the cor-rect position:

Printhead 1: BLACKPrinthead 2: CYANPrinthead 3: MAGENTAPrinthead 4: YELLOWPrinthead 5: GREENPrinthead 6: GRAYPrinthead 7: ORANGEPrinthead 8: BLUE

The inkset order in neoStampa is:12347856

Printhead 1: BLACKPrinthead 2: CYANPrinthead 3: MAGENTAPrinthead 4: YELLOWPrinthead 5: YELLOW (2nd)Printhead 6: MAGENTA (2nd)Printhead 7: CYAN (2nd)Printhead 8: BLACK (2nd)

The inkset order in neoStampa is:12347856

1.2 Calibrating device

Select the installed spectrophotometer for the measurement.

Device

Port

Transparency

Manual Mode

Select the measurement device to be calibrated and to be used in for the lineariza-tion.

Select the COM port where the device has been installed to. The button to the right allows to select Baud rate and Bits parameters. Read more in your device’s manual to learn how the serial port has to be set.

USB devices, such as the EyeOne will be recognized automatically.

This mode is to read transparent material, such as films using a back-light table.

Selecting this option will do single measurements meaning that every patch will be read one by one by pushing the button on your measurement device. Deselecting this option will measure the patches in scanning mode

If you have problems reading in scanning mode (e.g. the spacers between the patches are to narrow or cannot be recognized) try to turn this option on and read the linearization chart in manual mode.

Hit Next > to continue with the calibration wizard.

2.1 Single ink limit

Print the ink limit and combined linearization test chart and evaluate whether a pre-limitting of your printer is neces-sary.

Print...

Fast Dry mode

The first step is to print the chart and evaluate whether your printer has to be pre-limitted for linearization.

This option is for variable dot printers only. It will deactivate the largest dot in printing in order to prevent bleeding of colors.

Portrait / Landscape

Mirror

Horizontal Position

Vertical Position

Copies

Width

Roll / Cut Sheet

Print orientation in Portrait or Landscape mode. The chart is recommended to be printed in Portrait mode as the spacers are printed with the printhead direction.

Activate Mirror if you are printing onto transfer paper or to the backside of a trans-parent material.

Set an offset to the printers top position. The material will be moved forward to the distance set.

Set an offset to the printers left (or start) position. This number defindes the start point of the media width.

It’s recommended to print various copies to fill the material’s width.

Set the width of your material.

Define whether you are using a material on a roll or a cut sheet.

Important: If your printers inkset does not start with the following sequence you need to reorder the channels by selecting: 1. Black, 2. Cyan, 3. Magenta, 4. Yellow

The other channels (e.g. 05, 06, ...) do not have to be rearranged.

Check order

Print chart evaluation

To evaluate the test chart make sure that the print has dried and - if using textile material - fixated or steamed and washed.

Ink pre-limitting REQUIRED!

Ink-prelimitting is required because:

All of the 2-color-mix patches are bleeding (a) OR the darkest patches of the linearization strips are bleeding (b).

Follow the instructions

Ink pre-limitting not required

Ink-prelimitting is not required because:

neoStampa supports post-linearization ink cutting and if only some of the 2-color-mix patches are bleeding it’s possible to limit the ink after linearizing.

-> Proceed to chapter 2.2

Global ink usage

Ink limit per ink

If the printed test chart requires pre-limitting you can decrease the percentage of global ink usage in order to get less ink. This percentage will be used the same for all inks.

If the printed test chart requires pre-limitting you can decrease the percentage of each ink individually (e.g. if the yellow ink is bleeding more than another color). As this option allows more control it’s recommended.

If all of the 2-color-mix patches are bleeding you should first try to find out whether the material is not suited for the inks or the print has been made with a too high resolution. After you can try to limit globally or per channel and re-print the chart using the Print... button in 2.2. It’s recommended to try several ink limits until you reach a reasonable printout that does not require pre-limitting (see picture on top right).

If the darkest patches of the linearization strips are bleeding try to evaluate which darkest patch of each ink is free from bleeding and put the percentage in the appropriate ink box. The example on the LEFT shows that the best bleeding-free patch is at 80%, so we enter this percentage into the channels.

After setting the ink-prelimitting values reprint the chart using the Print... button in 2.2 as shown hereunder.

a) 2-color-mix patches b) linearization patches

2.2 Linearization

Calibrate the spectrophotometer and start with the linearization measurement.

Print...

Start

If a former ink pre-limitting was not required then you can use the printed test chart from chapter 2.1. If an ink pre-limitting was required (due to excessive ink bleeding) the reprint the test chart as described on top.

Connects with the spectrophotometer and calibrates the device. Make sure that your device is properly installed on your computer and the selected USB port is correct.

If the device refuses to connect try to close all other programs or restart your com-puter as the device or the port might be in use by another application or process.

Now read the selected linearization lines in strip or manual mode (as selected in chapter 1.2). Make sure that you read the corresponding color (e.g. when the yellow strip is selected read the yellow color) even though the order might be different.

The progress bar on the bottom left of the window shows the process and the strip or patch to be read. If the measurement has not been done properly ICCPrint will not continue to the next strip. Simply try to remeasure the marked strip or patch.

If one of the linearization strips cannot be read at all try selecting the Manual mode in chapter 1.2 and read the patches one by one. It’s possible that the device cannot recognize the patch difference or the spacers between the patch.

Read the Cyan color even though the first color in your printed test chart is a Black.

Proceed reading the Magenta color and so on.

2.2 Linearization - Densities

When finished reading the linearization strips or patches following window will automatically open. The curves show the measured values of the linearization chart. This window allows post-linearization ink cutting of the initially printed test chart.

auto-cut (a)density peak (b)

2-color-mix bleeding (c)

a)Calibration Wizard will automatically perform an automatic ink cut (a) based on the measured values. The example above shows a recommended auto ink cut to 95% as the measured patches of 95% and 100% have been equal.

b)By checking the density curve behaviour or density peak (b) and cutting to a reason-able value it’s possible to save ink costs. The example above shows that cutting the Black ink to 50% only a loss of 3 - 4% intensity compared to 100% will be obtained, but almost 50% of ink consumption can be saved!

c)By help of the test chart printed in chapter 2.1 or 2.2 it’s possible to analyze the 2-color-mix patches and find best or bleeding-free percentage (c). If none of the 2-color-mix patches are bleeding, no ink cutting is required.

The 2-color-mix patches are to be used for all colors (including other process colors, light colors and special colors) except Black. The Black can be cut independently but must be based on the conclusions of (a) and (b) as well.

It’s recommended to use Black in (c) around an average between 100% and the 2-color-mix bleeding result. (Example: If the 2-color-mix bleeding result is 75% for the colors, then (c) for Black can be 83%.)

Special note “Black”:

Enter the LOWEST percentage of these three informations (a), (b) and (c) into the ink cut boxes.

(a) auto-cut = 95%(b) visual density peak = 90%(c) 2-color-mix patches = 80%

(c) is the lowest number, so it’s necessary to put 80% into the yellow ink cut box

(a) auto-cut = 95%(b) visual density peak = 50%(c) 2-color-mix patches = between 100% and 80% (see Special note “Black”)

(b) is the lowest number, so it’s necessary to put 50% into the Black ink cut box

If the printer is equipped with a light color first perform the ink cut of all colors and black and then adjust the percentage until you reach a 50% of the dark color’s start value.

If the printer is equipped with both Gray and Light Gray color, first adjust the Gray percentage until it reaches a 50% of Black’s start value and then adjust the Light Gray percentage until it reaches a 50% of Gray’s start value.

IMPORTANT:

ColorExample

Conclusion

BlackExample

Conclusion

Light color

Gray / Light Gray color

Conclusion Color

Conclusion Black

Dark color start

decreasepercentage

If all of the inks have been cut in accordance to this tutorial hit OK to accept the parameters.

Enter Linearisation... to adjust and smoothen the linearization curves.

If you want to readjust the density curves or if you want to modify the ink cut per-centages you can reaccess the previous windows in Densities...

Activate the Smooth Curves option. This will use the high-quality 16-bit lineariza-tion engine giving you the best result.

IMPORTANT:

Select channel by channel and correct linearization errors by hand. Make sure that the Smooth Curves button is checked to use the maximum quality engine.

This button will perform an automatic curve repair of the selected channel. It’s recommended to manually correct curves as the auto-correct tool might not give the desired result.

This numbers have been set previousy under Densities, it’s recommended that these values should NOT be modified.

The maximum ink quanity will be set at a later stage. It’s recommended that this value should NOT be modified

These buttons or checkboxes will reset the measured linearization to a linear curve or will use the current curve for all other channels. It’s recommended that these but-tons should NOT be pressed.

Save the changes and proceed with the calibration.

Cancel all modifications and exit without saving.

Repair curve

Ink Level / Ink cut / Light ink cut

Ink Limit

All / Reset Ink / Reset All

Save...

Close

Select channel Correct curve

Activate Smooth Curves

2.3 Mixed ink limit

Print and evaluate the maximum ink quantity using the current densities and linearization curves

Print...

Start

Print the maximum ink quantity test chart.

Important: If your printers inkset does not start with the following sequence you need to reorder the channels by selecting: 1. Black, 2. Cyan, 3. Magenta, 4. Yellow

In the other channels the order does not influence the printout but make sure that NONE of the light colors are being selected!

Check order

Print chart evaluation

To evaluate the maximum ink test chart make sure that the print is dry. It’s not necessary to fix or steam it.

Select from the print chart the first bleeding free patches. The test chart for Mixed ink limit show values between 200 - 300%.

The example shows that in this printout the first bleeding free patches are at 255.

Enter the selected value into the Limit field.

Save all the parameters into a lut (look-up table) file by pressing the Save LUT... button. Enter a file name for this lut file in order to remember the calibration name.

Then hit Next > to continue with the calibration wizard.

bleeding free patches

3.1 Gray Substitution

The gray substitution is used when there is not gray ink available. The funcionality is to switch the black ink (based on a given percentage up to 0) by a mixture of CMY eliminating the dithering effect (optical effect that shows uneven color spots) Dithering effect: Without dithering effect when using gray substitution :

First select the gray substitution box. Then select from the dropdown list a patch file. There are two kinds of files, the ones ending with 2535 (for substitutions of 25 or 35% K) , and 5060 (for substitutions of 50 or 60% K).

Print a 2535 file, compare the two corners and choose the most accurate percentage (25% or 35%).If you observe a significant amount of dithering then print a 5060.

Patch files

How to decide

Print...

Select the file...

Adjust the page set up, position and orientation

Once we choose the CMY parameters that we want to switch we just need to change the values in their own field.The “Start“ field shows the k percentage in this example 25. the other fields are for the chosen CMY percentages.

Once the file is printed and the ink is chosen, select the patch. The center of the rectangle is teh CMY mix. The up right and down left corners show different percentages of black (K).

Observe carefully each patch under a good lighting and decide which gray you desire.

Example: In this case we want a 25% of K. We look for the mix of CMY that blends perfectly with the 25% of K (up right corner).

25% K

3.2 Black Addition

When the color black K 100% shows more like a dark gray (low color intensity) or if it tends to look “reddish” or “blueish”, it can be fixed by adding more black color.Print a patch file with a 100% K and other available color combinations.

Señect the patch file BlackAdd_CMYK if you only use the colors CMYK or CMYK with grays or light. But if you use other dark colors (blue, red, orange..) select the file BlackAdd_CMYK+(available colors).

For example, if the configuration is KCMYOBcm (K = black, C = cyan, M = magenta, Y = yellow, O = orange, B = blue, c = light cian, m = light magenta)... choose CMYK+2, since light cian and light magenta are not dark colors.

Adjust the page set up, position and orientation

Patch files:

Select the file...

Print...

The rectangle in the center is the black K 100% and the area around is the mix betwen the black the the other cho-sen colors.

Observe each patch under a good lighting and choose the one needed.

Once the patch is chosen enter the parameters in the value fields and leave the field “Start” with value 30 (only if you are not also using gray substitution).

IMPORTANT: If you are also using Gray Substitution (3.1), use the same value in both “Start“ fields.

If you are NOT using Gray Substitution:The “Start“ field for BLACK_ADD will be 30.

4.1 ICC Profiler patch printing

Print the RGB target file from your ICC RGB profiling software via ICCPrint. Select a target in the list of Patch file or import an RGB target by using the Add... button.

Patch file

Add...

Print...

Print configuration

Note:

Select the target in the list. Currently integrated RGB targets will be displayed in the list. If your desired target is not appearing you can add it with the button to the next.

Add other RGB targets by importing any of the files with the supported file formats. But make sure that the targets are real RGB targets as hueman CMS only supports profiling through ICC RGB profiling software.

Pring the RGB target using this button.

Set Page size, Orientation and Position and other settings.

It’s recommended that you print several targets as especially in textile fixation some drops from the fixation systems might destroy a printout.

Select RGB target...

... or import target

4.2 Generate printing Scheme

Measure and generate the ICC RGB profile with neoProfiler or with your ICC RGB profiling software and import the created ICC RGB profile with the Add... button.

Add...

ICC Profile

Save

Import the generated ICC RGB profile by using the Add... button (Step 1).

After importing select the ICC Profile in the list (Step 2).

Save the scheme with all information of lut and profile. This scheme will automati-cally appear in the Print Control‘s scheme list in neoStampa.

After saving you have successfully finished the calibration process and you can Exit ICCPrint.

2. Select ICC profile

1. Import ICC profile