Select brush tool from Photoshop toolbar
Set blending mode (Painting mode) to darken or difference etc
Apply brush tool with current Photoshop brush and color
Blending modes / Painting modes and Photoshop brushes tutorial and combining with difference modes etc in CC 2017 2015 2014 CS6 etc. You can use the blending modes before applying the brush. Set the blending mode to difference or darken etc and then apply the Photoshop brush. You can also apply the brush strokes in normal blending mode and then use the edit menu fade brush tool to set the blending mode to difference or darken etc as well as opacity. You can also apply the brush strokes to Photoshop layers and blend those via the blending modes in the layers panel. This tutorial shows a number of ways to apply brushes with blending modes
Select the brush tool
Select a brush
Go to the top bar of Photoshop
Select the blending mode / painting mode dropdown.
Set to 'Darken' 'Difference' 'Lighten' (the blending modes vary from version to version of Photoshop or PS Elements).
Apply Photoshop brushes to the document as normal.
You can apply the Photoshop brushes without ever touching blending modes by just applying them in standard normal blending mode. You can, if you wish, use the brushes with different blending modes in Adobe ® Photoshop ®.
They can be applied using difference / multiply / overlay / lighten etc blending modes (though these depend on the current image mode and channels) to achieve different brush strokes; you can also set the opacity say to 10% or 20% to create subtle additions of brush stroke.
The actual result will depend on the blending mode, the current color of the brush as well as the background color of the document. The image on the right uses blending mode "difference" and different colors.
Select brush tool
Apply brush as normal in Photoshop document
Fade brush tool
Set blending mode
Another alternative way of applying the brush using blending modes is via the edit menu and fade command which can fade the brush and change the mode. I really quite like using the edit menu command but it is one of those features that is not always accessible. If you have do some actions, the fade is gone for good and that is just such a pity as it would be great if the feature was 'live'.
Anyway, apply a brush stroke and then go to the fade and you can set the fade to darken or lighten etc blending mode as well as changing the opacity of the added brush stroke.
Layer menu and new layer
Apply brush strokes
Go to the layers panel
Set blending modes
Another alternative approach to applying the Photoshop brush strokes with different blending modes would be to apply the strokes to a layer and then use the blending modes of the individual layers via the Photoshop layers panel.
This is probably the slowest way of doing the blending modes but it is also perhaps the most flexible as the brush stroke and the layers can be removed in seconds or the blending mode changed to a new setting which is pretty useful.
1. Letter / alphabetical type brushes for Photoshop, PSP etc used in the examples