#mosaic effect

Start with a sketch.  I was heavily referencing the Byzantine mosaics found in Ravenna and Istanbul, so my sketch is boxy and simple.  The detail and structure comes from the shape of the tesserae, so there’s no need to put in a lot of fine lines in the sketch. In fact, you probably won’t be able to replicate really small details.

Next lay in the gold textures where you want guilding to be.  I used multiple layers of gold textures, piecing things by where I wanted the visual interest.  Blend the edges by erasing with a soft brush, but don’t make anything too smooth.  Sparkle comes from the difference between dark and light. You can see I placed the highest texture in the halo and in his chest, and darkened the sides by his arms a lot.  NOTE- I eventually found this color gold to be too warm, and cooled it down significantly.

Time to paint!  Try really hard to block things in without lines.  If you do draw lines, make them bold enough that they can serve as a line of tesserae in the finished piece.  Use motifs that echo the style you are going for, and the end texture will do the rest.

For example, I cribbed the diagonal square pattern on Molly’s coat from a famous mosaic in the Hagia Sophia. Also make note of the shifting line patterns of the gold tiles, which create a circular shape in Alexandros’ halo, while building mostly on geometric patterns in the background.  That’ll come up later.

Apply a stone texture to the painted section. Once again, it doesn’t have to be perfect or absolutely convincing, it just has to break up the brush marks that inevitably make up the underpainting. I went with a marbled look, but you can go in any direction you like.  Most Byzantine mosaics have satin polished stones making up the tesserae, so I wanted a smoother look.

Okay here is the magic part- Place a stone or plaster texture over the whole piece.  I used a photo of a plaster wall from textures.com, but I’m fairly confident anything will work.

Now darken the plaster texture to a midtone, something that matches very few areas of your underpainting, in terms of darkness levels.

Put the following layer style setting on your plaster texture layer.  There’s a purpose here- you are making a very tiny shadow around every tesserae you draw.  It makes a huge difference on areas of the finished painting where the tesserae colors are similar to the background color.  Lemme give you an example-

This is Molly’s hair without the Inner Glow styling.  See how you can hardly see the individual tiles on the lighter sections?

Here’s the same section WITH the layer styling.  Big difference.

Now- apply a layer mask to your plaster texture.  Set your texture to a lower opacity- say 70%. Get yourself a slightly geometric brush with hard edges.  Choose the color absolute black and choose your layer mask to paint on.  Set your brush to 100% opacity. Are you ready?

BEGIN TO PAINT OUT THE TESSERAE. This takes practice. You’ll probably have to go back and forth between making the texture layer 30% opaque and 70% opaque.  The goal is to be able to track the shapes you are making while still being able to see the underpainting.

This part takes a while to get the hang of and even after you’ve mastered it, it takes forever.  Keep turning your background to 100% opacity to check how it’s going.

My advice is to start with the outlines of everything.  I know I finished the face first, but by the time I was patching up the other interiors I had learned so much that I basically had to do mass parts of the face over again in their entirety.

At some point I decided that Molly’s skin wasn’t purple enough- color choice is one of my weaknesses, so I had sampled colors off of actual Byzantine mosaics.  They don’t really include violet as a tone at all, so I eventually had to make the decision to abandon historical accuracy in pursuit of lavender.

Okay so that’s the interior finished!

For the external background, I made a brush.  Well, I took a hard square brush and took away all size jitters and transfers.  Then, after a few lines, I added a 1% angle jitter so that it wouldn’t look Too Perfect.  Actual Byzantine mosaics have very regularly irregular backgrounds.  They try to make as much of it out of square stones as possible, but then they keep the matching ones all in one little patch and then just sort of bang that patch into other patches.  So, in an effort to imitate that, you can see my hastily-developed system. I picked a size and plotted out a small area in that size.  Then I built lots of other small areas of various sizes until they started to collide. I left the imperfect spaces alone, for a minute....

Then I went back and filled them with my hard brush, by hand.  This was an absolute necessity in curved areas, like the edge of the halo, but also looked really slick where tiles didn’t line up quite right.  It gave it that imperfect, handmade look.

Okay DAMN ALMOST DONE!  I made the damaged bits by taking a cloud brush, setting it to pure white, and going to town on the layer mask. When you feel good about the shapes, take a hard brush and bust up the edges to that it mostly takes out whole tiles instead of just... ghosting them to death.

NOTE-  I almost gave myself a heart attack because I forgot to duplicate the texture layer first and ended up having to recover the original finished pic from some Well of Lost Souls in the back of my computer.  So learn from that and do elegant damage AFTER DUPLICATING YOUR TEXTURE LAYER.