My objective in producing these tools is to provide a framework that makes it possible to paint a watercolor digitally so that it is impossible to tell whether it has been painted with paint and paper, or painted on a computer. I've checked out my own Photoshop paintings with a number of professional watercolor painters and they all thought that the paintings were traditionally painted watercolors. In fact they were very surprised that the paintings were digitally produced.
Of course, this is only possible if the digital painting is printed on watercolor paper, and if the printing is done correctly. In this article I outline the method that I use.
Having a good quality display that is calibrated is not exactly essential ... but it is nearly so, in my opinion. If your display is not calibrated then you cannot trust that the colors that you see on the screen are what they appear to be. If you view the painting on a different monitor, the colors will be different; and the print will also look different to the image on your display. So the first thing to do is to calibrate your monitor, and you can do this relatively cheaply with calibration equipment like the XRite i1 Display Pro. If you don't want to spend the money on a hardware calibrator then you could use software such as QuickGamma ... it's certainly not as good as a hardware calibrator, but it's better than nothing.
If you have your own printer then you should ideally also calibrate it ... but this is quite expensive and a bit technical. However if you want the best results then it is definitely worth doing. Professional calibration equipment like the XRite i1Pro is very expensive, but there are some good prosumer solutions like the XRite ColorMunki Photo which can be used for both monitor and printer calibration.
If you are getting your painting printed commercially then you should get the printer profile from the print shop (more about this later).
This is the single most important thing. It is absolutely not worth saving money on a cheap paper ... the result will be disappointing. I've tried numerous papers and by far my favourite is the Canson Infinity Arches Aquarelle Rag. It's a really beautiful 100% cotton-rag watercolor paper (it's a digital version of the famous Arches Aquarelle watercolor paper). Other paper mills like Hahnemuhle, Fabriano and St Cuthbert's Mill produce superb papers too, but the Canson Arches Aquarelle is my favourite. It has a wonderful texture and feel and produces brilliant colors.
You need to remove most of the texture and color from the background layer before printing. The paper has both texture and color, so you don't need (or want) it on the digital painting itself.
To remove the texture unlock the background layer and apply a Levels adjustment like the one shown here.
You can leave a little bit of texture, to taste, by not moving the center slider all the way to the left.
The background layer probably has no color (depending on which version of the Watercolor Tools you have). But if it does you can remove the color by using a Hue/Saturation adjustment on the background layer, setting the Saturation slider to -100.
You can get the icc profile for your printer/paper by:
Once you have the icc profile you need to install it on your PC or Mac. On the PC you right-click the icc file from Windows explorer and select Install. On the Mac you need to copy the icc file to Mac HD > Library > Colorsync > Profiles > Profiles.
You are now ready to soft-proof your painting on Photoshop. To do this, with your painting opened in Photoshop, do View/Proof Setup. You will be presented with a dialog box like this one:
In Device to Simulate, pick the icc (or icm) profile for your paper/printer. In this case I've picked iPF6400-Canson-Arches-240-i1Profiler-2584.icm which is a profile I created for the Canson Aquarelle for my Canon iPF6400 printer. If you don't see your profile in the drop-down list, restart Photoshop (it needs to be restarted after a profile install, otherwise it won't see the profile).
The other settings should be as shown.
You are now seeing the painting as it should appear in print. To toggle soft-proofing on/off press Ctrl-Y on the PC, Command-Y on the Mac. If your colors are not very saturated then you may see little difference. The blacks may appear a bit less black, which is OK (real watercolors will never have the kind of darks that can be produced on a monitor).
If the colors are very different ... and wrong to your mind ... it's because the printer is not capable of printing the colors on your digital painting (or possibly because you've set things up incorrectly, so check everything before trying again). You can either accept the colors as they are, or you can adjust them to bring them closer to what you would like them to be. To do this it's useful to duplicate the image and show it side-by-side with the soft-proofed image. You can then selectively adjust the colors that appear wrong until they are close to what you would like them to be. However you will not be able to get them to match exactly because the colors that appear wrong are wrong because the printer cannot reproduce them as they are.
If you are getting your painting printed by a print bureau then you've nothing more to do (you probably don't even need to resize the image as above, although it's useful to do it anyway as it take away a potentially destructive step from the print shop).
If you are printing your painting yourself, then in the print dialog you should make absolutely sure to:
If you follow these instructions you should get beautiful prints that are every bit as good as a traditionally painted watercolor.
It all probably seems very complicated especially if you haven't done it before (and it is a bit, to be fair), but this setting-up only needs to be done once: after that it's easy.
I hope this helps you with your printing!