The key thing with this tutorial is the custom tiles filter. The custom tiles uses a variety of methods to create a tile, one of those being paper / grains. You can use the standard grains but you can also create your own Painter paper textures. This tutorial uses self created grains.
You can create a Painter grain in many different ways but I have always found the easiest way is to use the paint tools and the Kaleidoscope tool. First create a Kaleidoscope / symmetry by clicking the Kaleidoscope tool in the Painter toolbox and then set the segment number. I often go for about 12 to create more interesting and complex symmetrical designs. Using some of the brushes with the Kaleidoscope on can result in fairly sluggish painting (this depends on the machine). Anyway, apply the brush strokes to create a seamless tile (so avoid the edges)
Now use the select menu command. Select all. Now go to the window menu and paper panels and select the paper etc panels. Now go the right side and select the capture paper option. You might also like to save as a PNG image and then set the custom icon for it (though I cannot work out why it can't just save the default custom icon as the same as the paper grain - very strange). OK, now you have the paper texture / grain, select the paper grain in the Painter's paper library (it should be selected but if it is not, select it).
You can find the custom tile filter in the effects and esoterica filter menu of Painter. Set the 'use grout' to OFF. Set the thickness to the maximum. Threshold to fairly high such as 230. This does require some experimentation and varying of the size of the paper tile via the paper panel (small seems to work best). Depends on the image size, sometimes the end result is a total blur but fairly small tiles should be effective. Also, repeat applications of the custom tile filter with a varying size of paper tile can be effective.
Now the custom tiles have been applied, you can then add the 3D paint effect via the apply surface texture filter (found in the effects menu found in the surface control menu. Use the image luminence option and vary the light direction.
The above shows the end result of the paper textures / custom tile and apply surface texture. You can, at this point, repeat the process with another grain and a different set of surface texture settings. Also, you can apply the custom tile and apply surface texture using different tiles such as lines and warped shapes