Troubleshooting with Duotones in Photoshop
Duotone is a file made up of 2 spot (or pantone) colours.
Printed files are generally output as CMYK (Cyan, Magenta, Yellow and Black) colours, but ask your Account Manager at Dobson’s if you are unsure.
Computer screens use RGB (Red, Green, Black) colours.
Therefore, if your file is going to be output using different colours, then Duotones need to be converted in Photoshop before the file is used in an external application. Unfortunately, converting Duotones often results in dirty or dark colour conversions.
For example, blues tend to get yellow and black added to them.
Duotone (or Monotone/Tritone/Quadtone) images must have the colours defined correctly from the PANTONE library to ensure colour integrity. Don’t use the colour mixer. Messing with the tone curves within the Duotone is ok.
Duotone (as a colour mode in Photoshop) needs to be saved as an EPS file before using in external applications like InDesign to reduce the likelihood of colour issues. For consistency, it is good to save a Duotone Curve from a common image and use that as a starting point for all the other duotones in the job.
Here are some more problems with Duotones and solutions for the Adobe Creative Suite:
Adobe Creative Suite handles general colour management globally when it is first setup. The default profiles are very general and don’t give you the best results possible from your individual hardware (monitor/scanner/printer).
Where possible, check each application (Acrobat/InDesign/Photoshop/Illustrator) “Colour Settings” has the right profiles selected.
For example, for RGB profile:
Your monitor profile (if calibrated) will show in the list of available profiles. If it isn’t there, then sRGB IEC61966-2.1 is a suitable fallback.
For CMYK profile, select your colour output device as the default profile. If you don’t have one or don’t use it regularly, it is better to choose the most generic CMYK possible (e.g. colourSync CMYK – Generic CMYK Profile).
Output profiles “adjust” colours in the background to suit their requirements. If you use more than 1 output device it is best to leave your colours as you have created them and let the individual output device apply a specific profile to the job at output time.
Lastly, ensure there are no transparent effects (particularly Mode: Multiply) being applied to the duotone. Most transparency effects work by generating colours that aren’t already present to visually generate the effect.
Of course, technical issues are common which is why our outstanding prepress team is so important. To avoid most problems with colour, make sure you check your proofs thoroughly. Proofs are then compared to what comes off press, in order to ensure the colour is exactly what you want!
As always, if you encounter any technical issues or have any questions, let us know as your Dobson’s Account Manager will be more than happy to help.
