Iconic pieces of art are sprinkled throughout the New York City subway system. They adorn the walls of subway stations in the signage and embellish the subway tile walls. Tile mosaics are a throwback to the days of old world craftsmanship that was used to build the subways. No doubt they would be expensive and time consuming to produce today.

Here is my take on reverse engineering the process to come up with something easy so can create your own custom sign in the style of the NYC Subway mosaic with a few modern materials.

Step 1: Bits and Pieces...

Mosaics are pieces of tile that have been placed together to form a larger piece. Like a quilt, the small pieces can be artfully arranged to form a design. It takes a lot of work to cut those pieces to fill and fit into a design.

Here, I will try to replicate the mosaic look with air dry polymer clay and paints. No need to deal with real tile fragments, tile cutting tools, masonry cement and grout.

You will need:

A stiff board or plank that will be the underlying base for your project. It should be cut to the size of your final design. I pieced together more scraps of the MDF wainscoting that I had used for Personalized Street Signs. I used wood toothpicks as reinforcing dowels and had sandwiched the seam on both sides with paper facing pulled from a piece of corrugated cardboard. My mosaic board size is about 27 x 7 inches.

Air hardening polymer clay, I used an entire 2 lb container. You could do with an oven bake polymer clay but there would be an extra step in getting your project into the oven to cure. My clay was all a generic white color. You can get the clay in different colors which would save you a step in painting but they would be basic colors which would probably not suit your design.

Some fiberglass mesh drywall tape, gauzy strip bandage or fabric mesh - save those onion bags - to use as a gripper layer to keep your mosaic together as you build it

Various paints. Acrylic for easy cleanup.

Cornstarch or baking soda powder to thicken paint/glue or a 3D fabric paint to simulate the grout.

I also used Gloss Mod Podge. It works to give the bare "tiles" its glassy fired glaze look.

Step 2: Times New Roman...

You can try any design you like.

For text, pick a font that resembles what was used for the real subway mosaics.

I used Times New Roman.

Print out your text to fit your backer board. I used 400 point font size and taped together the printout.

Since this will be your building template, draw on guide lines for your border tiles.

I guess you could have a complete design laid out in graphics software but I just printed out the text from Wordpad and went from there.

Cover your entire design with packaging tape. This is optional but I didn't want my clay sticking to the template.

Now give it a layer of the fiberglass mesh drywall tape. You can overlap strips to form a complete sheet over the entire design. There is a slight adhesive to the drywall tape so press it down to prevent shifting when you lay clay on top of it.

Step 3: S P Q R

Creating mosaics is a classical art form. I guess it has been around ever since the invention of pottery...at least since the first person who dropped one.

With the project board prepped with a layer of drywall tape, start forming the characters in the design.

Press the clay into the mesh so it will stick when it dries.

Just cover up the printed character which is your guide.

Flatten to an even thickness, about 1/8 th of an inch. Not too thick as to waste clay but enough so it doesn't fall apart and crack while drying. I guess I should have made some kind of height or depth thickness gauge but it all adds to the handmade mosaic character with various tile thicknesses.

Next, use whatever is at your disposal to help shape the letter.

I used the barrel of the permanent marker to roll things flat. I used some popsicle sticks with the ends cut in various shapes. I also used my utility knife blade. You could probably run the clay through a pasta maker to get a long strip of material to use but I use mine to only make food just like the toaster oven is...wait...

Mark the tile break lines, score lightly with any of your shaping tools and then make deep impressions on the lines. The lines don't have to go all the way through to make a separate tile, just deep enough so we can fill it in with our substitute glue/paint grout. You will probably have to go back a few times to clean up any of the edges that got deformed by cutting a line on the adjoining piece. Use your fingers to smooth out any burrs from dragging the tools through.

Take a look at examples of real mosaics to see the pattern they use to form the letters. Try to imitate that style or go with your own.

Step 4: Borderline...

With the letters all formed, we can work on forming the border around the design.

This gives the letters inside a chance to start hardening up. It makes it easier to fill in between them if you have something solid to press against.

Start placing strips of clay on the border regions. Press into the drywall mesh.

Flatten to an even thickness and inscribe the tile lines. Use any tile pattern you like.

Now go in to fill the interior spaces between the letters. Press in pieces of clay that are roughly shaped to the space.

Press in, flatten, and inscribe the tile lines.

You can work on little sections at a time and just blend in the next piece of clay to fill out the rest of the section.

I wasn't sure if I had enough clay to finish the project so the interior layer is a little thinner to conserve the amount of clay used. It seems to add to the 3D effect that the letters are embossed.

I used the entire 2 lb pail of clay.

Step 5: Not Quite Watching the Paint Dry...

Let your workpiece dry and harden overnight.

You may or may not need to do this next. If you want to speed up the air hardening of the piece, you will need to expose the back of the work.

Take your backer board and cover the front of your design.

Carefully support everything and flip it over.

Carefully peel off the design template off the back. The drywall mesh should still be intact with the clay embedded in it.

Let your workpiece dry again. Resist the urge reshape any portions that are still not dry.

Put the backer sheet back in position and flip it over with your backer board.

Be prepared for shrinkage. It just happens.

The dried result will probably turn out all wrinkly and warpy. Don't worry about that too much.

Gently flatten out sections if you can by pressing them back into shape. The pieces should be able to bend at the tile cut lines or crack along it.

Step 6: Paint by Numbers...

If you didn't use different colored clays for your mosaic, we can just paint the tiles.

Find the smallest brush you have.

Reference real subway mosaics to get a feel for the color scheme used.

My mosaic will have white letters on a blue background. The border will be trimmed in yellow and green.

Note that mosaics use a variety of tile pieces which all have slight variations of color and are mixed randomly when placed to give it that mosaic character.

I started out with what would be some red accent pieces in the blue field.

From my mega acrylic paint sampler set I found two close shades of blue to use for the field. Use one shade to randomly color first and then the next to complete the field.

Since the field did not have deep lines for grouting later on, I painted in those lines.

To get a more historically accurate shade of yellow, I mixed a batch of bright yellow with some orangey yellow. The secondary color was more yellow added in.

I did the same thing for the blue border tiles. I mixed a blue with the rest of the yellow that remained to get a green and added a drop of teal. The darker green was made by adding a little more teal.

The outside tiles were larger so I didn't really have to color in the lines since the grout will fill that in. They were also easier to paint since the individual tiles were bigger than the fine tip brush I used and didn't accidentally get too much paint on the adjoining tile which was a different color.

When all painted and dry, I gave it a coat of Gloss Mod Podge all over. This is to get that nice sheen of ceramic tile and to make it easier to clean off when we apply the grout.

Step 7: All a Board...

It is now time to permanently mount it to the backer board.

Apply glue to the backer board.

Slide your mosaic off the backer sheet onto the glue.

Try to flatten as much as you can. Reposition any loose pieces if they broke off.

Get more scrap backer board to sandwich in your mosaic.

Clamp down to further flatten out the mosaic and let it dry.

I would recommend placing a sheet of plastic wrap over your mosaic to prevent it from sticking to the clamping boards. I had turned it over several times getting the clamps in place and the glue seeped through in places to the front.

Step 8: Fill in the Blanks...

I gave my mosaic an extra coat of Mod Podge to help with the grouting process.

In real tile work, grout is used to fill in the cracks and seams between tiles. It is powdered rock, cement and sometimes sand for extra filler.

We don't need to use real grout since we can make a faux grout.

Mix up a batch of grey acrylic paint and add enough cornstarch or baking soda powder to form a thick paste.

Spread the paste over a small section of the mosaic to be grouted. Work it into the big gap at the edge.

Since the area is small, use a popsicle stick to apply and scrape off as much excess as possible. Make sure you get grout deep in the cracks and crevices. Use a dampened paper towel to spread and float everything even smoother.

Next, use a damp sponge that has been wrung out to mostly dry to start wiping off the excess grout. Rinse and repeat often. Change your wash water often. You just want to make light diagonal passes over the tiles just to remove the excess grout on the tiles and not out of the seams. When mostly clean, I went over with a dry paper towel to wipe the tile surfaces hoping to get off that haze that forms from the paint dissolved in the wash water. I think a real polyurethane clear coat or a more water resistant type of Mod Podge would have helped shed the grout wash better. Although, it gives it that je ne sais quoi weathered grimy look.

So now you are ready to go retile your bathroom or kitchen.

Wait overnight for everything to dry.

Go install your new piece of classical art.

Hang on a wall or place it up on the fireplace mantle.

Enjoy!