My husband is under the impression that because I am a ceramic artist, I basically get to play all day and have a grand old time in the studio. I constantly have to dissuade him of the misunderstanding that tile making epitomizes the proverbial “fun and games”. While overall rewarding, it is like any other job, a smattering of interesting and enjoyable aspects, interlaced with a healthy helping of drudgery and tedium.
For instance, I absolutely love the design process: coming up with new tile ideas, filling my sketch books with numerous doodles, planning projects and the like. It sparks my imagination and serves as an outlet for my creativity. And even though some people may think it is dull and monotonous, I also really enjoy carving, whether it be creating a hand-carved wall hanging (like The Endless Knot Poem Plaque), or decorating a sgraffito plate. But unfortunately, my work also includes tasks I do not enjoy as much – tile pressing, I’m looking at you!
Newly pressed Knot Number Tiles.
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The Tile Making Process page in our About section outlines the techniques we use to create out tiles. Some of the tiles, plaques, coasters, etc that Blue Willow Studio creates are made as one-off items, carved or decorated individually (like our Leaf Impression Plates or Sgraffito Plates). However, we also use the traditional technique of tile pressing from plaster molds. A plaster mold is created from an original tile (see my post Making a Plaster Press Mold for a Tile for more information about mold making). The mold is then used to accurately and quickly replicate the tile in order to produce copies that present a more affordable tile option.
But pressing a tile from a mold is really not the most exciting task in the studio. In fact, I find it boring and uninspired. However, it is a necessity for tile making – it’s just one of those things that need to get done so you can move on to something a bit more fun. So, if I have not turned you off to tile making using press molds, let’s go back to the basics and press a tile!
But pressing a tile from a mold is really not the most exciting task in the studio. In fact, I find it boring and uninspired. However, it is a necessity for tile making – it’s just one of those things that need to get done so you can move on to something a bit more fun. So, if I have not turned you off to tile making using press molds, let’s go back to the basics and press a tile!
Project:
Pressing a Tile Using a Plaster Press Mold
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Materials:
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Step 1: Make a Clay Slug
I begin the pressing process by making a bunch of clay slugs, which are basically slabs of clay that fit into the mold cavity. Some people just use lumps of clay, not really measured out, but I find the process goes more smoothly if the clay slugs are measured to the dimensions of the mold cavity.
A stack of clay slugs ready to be pressed into tiles.
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♦ Roll out a slab of clay to a thickness slightly thicker than you tile.
Yippee another slab! If you have any questions about rolling out a slab, see my tutorial Back to Basics: Slab Rolling.
In this tutorial I will be pressing one of my Celtic Knot Alphabet Tiles. The cavity for the tile is about ½” thick. I want to have enough clay to fill the cavity, plus a little extra, so I roll my slab out to 5/8” thick. I use my trusty slab roller to create my slab, but of course you can use your preferred technique, whether it be rolling with a pin, or stretching the slab on your work table.
Yippee another slab! If you have any questions about rolling out a slab, see my tutorial Back to Basics: Slab Rolling.
In this tutorial I will be pressing one of my Celtic Knot Alphabet Tiles. The cavity for the tile is about ½” thick. I want to have enough clay to fill the cavity, plus a little extra, so I roll my slab out to 5/8” thick. I use my trusty slab roller to create my slab, but of course you can use your preferred technique, whether it be rolling with a pin, or stretching the slab on your work table.
♦ Smooth the surface of the slab using a rubber rib or other clay smoother.
Since I use a slab roller with canvas, the canvas leaves a bit of a texture on the resulting slab. I have found that sometimes this texture survives even the force of the pressing process, and my resulting tile sports some unwanted patterning on its face. Therefore, I always smooth the canvas texture from the surface of a slab before pressing.
Since I use a slab roller with canvas, the canvas leaves a bit of a texture on the resulting slab. I have found that sometimes this texture survives even the force of the pressing process, and my resulting tile sports some unwanted patterning on its face. Therefore, I always smooth the canvas texture from the surface of a slab before pressing.
A clay slab rolled to a 5/8" thickness. A template for the clay slug is placed on top of the slab.
♦ Cut the slab to the dimensions of the tile mold.
The mold cavity is a bit over 4” wide by 5.5” long. Since I usually press a bunch of these tiles at one time, I have created a rectangular template for the slug so that I do not need to measure the dimensions for each cut. (If you have one on hand, a cookie cutter or clay cutter speeds up the process even more.) I place the template on the slab of clay, and cut the slug out using a clay knife. I can usually get a few slugs per slab.
The mold cavity is a bit over 4” wide by 5.5” long. Since I usually press a bunch of these tiles at one time, I have created a rectangular template for the slug so that I do not need to measure the dimensions for each cut. (If you have one on hand, a cookie cutter or clay cutter speeds up the process even more.) I place the template on the slab of clay, and cut the slug out using a clay knife. I can usually get a few slugs per slab.
Cutting a slug out of the slab using a clay knife and a paper template.
Step 2: Prepping for the Press
♦ Make sure the mold cavity and face are clean and free of debris.
I try to keep my molds as clean as possible, which, I must say, requires some effort in a ceramics studio! After first creating a press mold, I clean off any residual plaster or clay with a damp sponge. I also clean my molds after each use, since they tend to accumulate bits of clay. However, if I have been storing the mold for a while (especially in a garage or out building), the mold cavity may have accumulated some dirt and grime. Before using the mold, clean out the cavity so that your tile does not pick up any of the dirt. If there are only a few specks of smut, I blow them out or use a paint brush to sweep them away. I also use a damp sponge to remove any stubborn grime.
I try to keep my molds as clean as possible, which, I must say, requires some effort in a ceramics studio! After first creating a press mold, I clean off any residual plaster or clay with a damp sponge. I also clean my molds after each use, since they tend to accumulate bits of clay. However, if I have been storing the mold for a while (especially in a garage or out building), the mold cavity may have accumulated some dirt and grime. Before using the mold, clean out the cavity so that your tile does not pick up any of the dirt. If there are only a few specks of smut, I blow them out or use a paint brush to sweep them away. I also use a damp sponge to remove any stubborn grime.
Tip: When I press a new mold for the first time, I have noticed that sometimes there are residual plaster flakes in the mold cavity from when I made any touchups. I use a 1.5” paint brush to whisk any plaster or clay from the mold. Then, before pressing the first tile, I take a piece of scrap clay and press it firmly into the mold to pick up any pieces of stray plaster.
The clay slug has been placed in the mold cavity.
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♦ Lay the clay slug into the mold cavity and press using your fingers.
Maybe it’s just the clay I use (Standard 420, a stoneware clay with lots of grog), but I find that if I just lay the slug into the mold and move on to the pressing step, the clay does not make its way into all the corners of the mold. Therefore, I like to press the clay into the mold using my fingers, especially into the corners of the cavity. I don’t use too much force, but I make sure that the clay enters the tighter spots of the design.
Maybe it’s just the clay I use (Standard 420, a stoneware clay with lots of grog), but I find that if I just lay the slug into the mold and move on to the pressing step, the clay does not make its way into all the corners of the mold. Therefore, I like to press the clay into the mold using my fingers, especially into the corners of the cavity. I don’t use too much force, but I make sure that the clay enters the tighter spots of the design.
Pressing the clay slug into the mold cavity, making sure to fill the corners.
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Clay pressed into mold cavity.
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Step 3: Press the Tile
♦ Cover the clay with a piece of cloth, and place a board on top of the cloth.
I usually use a rag or a scrap piece of canvas for my covering cloth. It doesn’t have to be too big, just large enough to cover the clay – maybe about a foot square. The cloth will protect the pounding board from the clay and make cleanup easier.
For a pounding board I use a piece of scrap wood, about 9” square and about a half an inch thick. This board is placed over the cloth and will help to even out the force of the pressing mallet across the surface of the tile, protecting the mold from the mallet.
I usually use a rag or a scrap piece of canvas for my covering cloth. It doesn’t have to be too big, just large enough to cover the clay – maybe about a foot square. The cloth will protect the pounding board from the clay and make cleanup easier.
For a pounding board I use a piece of scrap wood, about 9” square and about a half an inch thick. This board is placed over the cloth and will help to even out the force of the pressing mallet across the surface of the tile, protecting the mold from the mallet.
Yup, my set up is pretty low-tech. A rag I had lying around the house serves to cover the clay, protecting the pounding board.
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A scrap piece of wood covers the clay and rag and works well for the pounding board- no need to buy anything new and fancy!
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♦ Pound the board with the rubber mallet.
I like to hold onto the board to steady it as I press the tile. My pounding board happens to have a spur of wood sticking out from one side that I use as a handle. I start in the center of the board and work my way out and around the tile, striking with a significant amount of force. This process will ensure that the clay is pressed firmly into the mold cavity and fills all the indentations of the tile design. If too little force is applied, the tile will lose detail, or come out of the mold with unwanted creases and crevices.
It takes less than a minute to compress the clay into the cavity using this method. The number of strikes with the mallet will vary depending on the size of your tile and the moisture level of your clay (softer clay will fill the mold easier than drier or naturally stiffer clay) – just experiment and learn!
I like to hold onto the board to steady it as I press the tile. My pounding board happens to have a spur of wood sticking out from one side that I use as a handle. I start in the center of the board and work my way out and around the tile, striking with a significant amount of force. This process will ensure that the clay is pressed firmly into the mold cavity and fills all the indentations of the tile design. If too little force is applied, the tile will lose detail, or come out of the mold with unwanted creases and crevices.
It takes less than a minute to compress the clay into the cavity using this method. The number of strikes with the mallet will vary depending on the size of your tile and the moisture level of your clay (softer clay will fill the mold easier than drier or naturally stiffer clay) – just experiment and learn!
Using a rubber mallet to compress the clay into the mold cavity.
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More pounding with the rubber mallet. This can be quite loud, so wear your ear protection!
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Tip: Pressing a tile using the pounding method is quite loud. In order to protect my ears, I always wear ear plugs.
Step 4: Clean the Back of the Tile
♦ Using a straight scree board, remove the excess clay from the back of the tile.
Since my clay slug contained a bit more clay than my mold needs, there is excess clay on the back of the tile after the slug is pressed into the mold. I use a small piece of 1x2 lumber (approximately 12 inches long) to scrape the extra clay off the back of the tile and the mold sides. The board should be longer than the width of the tile, with ample space on the ends to grip.
Since my clay slug contained a bit more clay than my mold needs, there is excess clay on the back of the tile after the slug is pressed into the mold. I use a small piece of 1x2 lumber (approximately 12 inches long) to scrape the extra clay off the back of the tile and the mold sides. The board should be longer than the width of the tile, with ample space on the ends to grip.
A scree board (here a short piece of 1 x 2) will be used to remove the excess clay from the back of the tile. Again, I just used a piece of scrap lumber I had lying around the garage.
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Beginning in the middle of the tile, place the scree board lengthwise against the face of the mold across the tile cavity. Make sure that each end of the board is resting on a side of the mold. Applying downward pressure to the board, pull it towards you to remove the extra clay and flatten the back of the tile. The clay of the tile should be level with the sides of the mold. If there is a lot of extra clay, an extra pass or two with the board may be required - no need to remove it all in one go. Turn the mold and scrape the other half of the excess clay from the tile.
Removing the excess clay from the back of the tile and mold using a scree board.
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I have already removed the clay from one end of the mold. I flip the mold around and remove the clay from the other end.
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Tip: It is tempting to begin removing the excess clay from the top of the tile. However, this will pull the tile clay away from the edge of the mold, thus warping the finished tile. Start the cleaning of the excess clay from the middle of the tile to avoid this warpage.
♦ Smooth the back of the tile with a rubber rib.
The surface of the back of the tile is usually a bit rough after removing the excess clay, especially if you are using clay containing a lot of grog. I smooth the back of the tile with a rubber rib.
The surface of the back of the tile is usually a bit rough after removing the excess clay, especially if you are using clay containing a lot of grog. I smooth the back of the tile with a rubber rib.
Smoothing the rough surface of the back of the tile with a rubber rib.
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Step 5: Signing and Notching the Tile (Optional)
The following steps for finishing the back of the tile are all optional. Pick one or a couple, or leave the back of the tile smooth and unmarked!
♦ Sign the tile.
I use a custom stamp to impress the Blue Willow logo onto the back of the tile as my signature. You can also just sign your name into the soft clay with a carving tool.
♦ Sign the tile.
I use a custom stamp to impress the Blue Willow logo onto the back of the tile as my signature. You can also just sign your name into the soft clay with a carving tool.
Stamping my Blue Willow Studio logo into the back of the tile.
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♦ Create a hanging notch in the back of the tile.
At this point I like to impress a small notch on the back of my decorative art tiles so that they can be easily hung once fired. Of course, if you plan to affix your tile permanently to a surface using tile mortar or another sort of adhesive, this step is unnecessary.
You can make a notch using a wide range of implements. I use a small chisel-like tool or a wooden sculpting tool inserted into the clay. It would probably be wise to ensure the notch is centered on the back of the tile by measuring, but I usually just eyeball it. The notch is about ½” long, so that the tile can be adjusted once on the wall.
For my Knot Number Tiles, I prefer making screw holes in the tiles so that they can be securely affixed to an outside surface. I cover making the screw holes in Step 8 below.
At this point I like to impress a small notch on the back of my decorative art tiles so that they can be easily hung once fired. Of course, if you plan to affix your tile permanently to a surface using tile mortar or another sort of adhesive, this step is unnecessary.
You can make a notch using a wide range of implements. I use a small chisel-like tool or a wooden sculpting tool inserted into the clay. It would probably be wise to ensure the notch is centered on the back of the tile by measuring, but I usually just eyeball it. The notch is about ½” long, so that the tile can be adjusted once on the wall.
For my Knot Number Tiles, I prefer making screw holes in the tiles so that they can be securely affixed to an outside surface. I cover making the screw holes in Step 8 below.
Using a small chisel tool, I create a notch in the back of the tile to facilitate hanging once the tile is fired.
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♦ Create mounting grooves.
If you plan to permanently grout your tile to a surface (backsplash, floor, etc) you can carve mounting grooves into the back of the tile instead of notching it. Grooves are not necessary for setting tile, though they do allow the tile to grip the tile mortar a little better.
I either use a metal carving tool with a wide scoop at the end or a curved wooden sculpting tool to carve the grooves into the back of the tile. I try to spread the grooves out evenly across the back of the tile, but I don’t waste time measuring them out perfectly. I create maybe 5 grooves in the back of a 4-inch tile, but you can create however many you would like.
If you plan to permanently grout your tile to a surface (backsplash, floor, etc) you can carve mounting grooves into the back of the tile instead of notching it. Grooves are not necessary for setting tile, though they do allow the tile to grip the tile mortar a little better.
I either use a metal carving tool with a wide scoop at the end or a curved wooden sculpting tool to carve the grooves into the back of the tile. I try to spread the grooves out evenly across the back of the tile, but I don’t waste time measuring them out perfectly. I create maybe 5 grooves in the back of a 4-inch tile, but you can create however many you would like.
Using a rounded wooden sculpting tool to create grooves in the back of the pressed tile.
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Since my clay contains grog, the grooves are a little rough around the edges when I first create them. I just go back with a finger or the back of the carving tool to smooth them out a bit – I don’t want any sharp edges that have the potential to cut fingers once the clay is fired.
Carved mounting grooves in the back of the pressed tile.
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Closeup of mounting grooves
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Step 6: Wait
♦ Place the mold face down on two runners.
I use two lengths of 1 x 2 furring strips to prop the mold above the work surface. And now we play the waiting game. The plaster is porous and will wick moisture out of the clay, shrinking the tile and allowing it to drop out of the mold. This usually takes at least a half an hour for me, sometimes longer depending on how moist my clay is and how many times I have used the mold that day.
I use two lengths of 1 x 2 furring strips to prop the mold above the work surface. And now we play the waiting game. The plaster is porous and will wick moisture out of the clay, shrinking the tile and allowing it to drop out of the mold. This usually takes at least a half an hour for me, sometimes longer depending on how moist my clay is and how many times I have used the mold that day.
The pressed tile mold sits face down on a couple runners drying enough so that the tile can be easily removed from the mold.
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Tip: Sometimes the tile needs a bit of encouragement to release from the mold. Use the rubber mallet to tap gently around the edges of the mold, or lift one side of the mold an inch or so off the runners and let it fall back into place. These two methods create vibrations that help to release the tile.
Step 7: Clean the Tile
♦ Smooth the rough edges from the tile and repair any defects.
Once the tile has come out of the mold you will probably notice that at least the bottom edges are a bit rough. These will have to be smoothed down at some point, because once the tile is fired, the edges will be sharp enough to cut skin. Some people wait until the piece is in a firmer leather-hard state, or even at the bone dry state to clean. Personally, I think the best time to clean the tile is when it first comes out of the mold. The clay is still moist and forgiving and easy to manipulate, and cleaning does not create dust at this point
Once the tile has come out of the mold you will probably notice that at least the bottom edges are a bit rough. These will have to be smoothed down at some point, because once the tile is fired, the edges will be sharp enough to cut skin. Some people wait until the piece is in a firmer leather-hard state, or even at the bone dry state to clean. Personally, I think the best time to clean the tile is when it first comes out of the mold. The clay is still moist and forgiving and easy to manipulate, and cleaning does not create dust at this point
The bottom edges of this tile are a bit rough and will be smoothed down before drying.
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If there is any excess clay around the edges of the tile, I use a knife to trim it off. I then use my finger to smooth down the bottom edges so that they are nice and rounded.
Smoothing the rough edges of the newly-pressed tile with my fingers.
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At this point I also check the face of the tile to make sure that the design has come through clearly and there are not any significant defects. Sometimes, the pressing will result in a minor crease or divot. Using my fingers or a small rounded metal tool, I smooth out any minor imperfections. (Of course, if there are major defects, I just scrap the tile a press it again.)
Step 8: Screw Holes (Optional)
♦ Using a clay hole punch or just a drinking straw, pierce screw holes through the tile.
Instead of the hanging notch mentioned in Step 5 above, sometimes I prefer to make screw holes in the tile for a more secure hanging method. For instance, I use screw holes in my Knot Number Tiles since they are usually used as house numbers where they must be affixed sturdily to an outside surface.
Instead of the hanging notch mentioned in Step 5 above, sometimes I prefer to make screw holes in the tile for a more secure hanging method. For instance, I use screw holes in my Knot Number Tiles since they are usually used as house numbers where they must be affixed sturdily to an outside surface.
A clay hole punch and a drinking straw - both good tools for creating holes in clay.
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In order to make the holes, I use a hollow instrument, such as a clay hole punch or drinking straw, to remove a core of clay from the tile. Each instrument has its benefits. A clay hole punch is made of metal and therefore quite sturdy. But it must be purchased from a ceramic supply store. A drinking straw is basically free (just save one from your next restaurant drink purchase). However, since it is made of plastic, it will not last as long as hole punch, and can warp a bit when creating the hole.
Tip: Using a hollow instrument to make the hole (instead of a solid instrument like a chopstick or a skewer) allows for less distortion of the tile since the excess clay is removed.
Pierce the face of the clay with the straw and press down through the clay until the straw hits the work surface. When the straw is removed, a core of clay comes with it. I use a skewer to push the core of clay out of the straw, and it is ready for the next use.
Using a piece of a drinking straw to cut a screw hole through the clay of the tile.
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The back of the hole is usually a bit rough, so I flip the tile over and round out and smooth the exit using my fingers and a wooden skewer.
Using a wooden skewer to clean the edges of the back of the screw hole.
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Using my fingers to smooth out the clay around the back of the screw hole.
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Step 9: Let the Tile Dry
♦ Allow the tile to dry slowly.
Move the tile to its final drying location, and allow the tile to dry slowly. I dry my flat tiles sandwiched between two sheets of drywall. The drywall wicks the moisture from both the front and back of the tile, allowing the tile to dry evenly. I set my high relief tiles on a sheet of dry wall and cover them with a plastic tarp to slow down the drying process a bit in an attempt to decrease warping. Refrain from moving the tile after you have cleaned it to prevent any accidental damage or warpage. Drying can take days to weeks, depending on the temperaments of the clay and the drying atmosphere.
Move the tile to its final drying location, and allow the tile to dry slowly. I dry my flat tiles sandwiched between two sheets of drywall. The drywall wicks the moisture from both the front and back of the tile, allowing the tile to dry evenly. I set my high relief tiles on a sheet of dry wall and cover them with a plastic tarp to slow down the drying process a bit in an attempt to decrease warping. Refrain from moving the tile after you have cleaned it to prevent any accidental damage or warpage. Drying can take days to weeks, depending on the temperaments of the clay and the drying atmosphere.
Make sure your tiles are completely bone dry before firing, as moisture trapped in the tile can cause breakage in the kiln. I have noticed with the Standard 420 clay I typically use, that even if the tile looks bone dry, it may not be completely dry. After drying to a visible bone dry as described above, I carefully move my tiles to a well-ventilated drying rack with slotted shelves to allow more air circulation. I keep them here for a number of days, sometimes employing a fan, to ensure they are fully dry.
And there you have it – your first pressed tile!
Tip: Keep your studio dust free by cleaning all your tools and your mold after use, or even during use if residual clay begins to dry and flake. Also, the protective cloth will become dusty if it dries out, so clean the cloth frequently.
Epilogue:
Other Methods of Pressing
The pressing technique describe above is the most basic, but there are other way to press a tile that can speed the process up a bit, namely using a mechanical press.
Frank Georgini, in his book Handmade Tiles: Designing, Making, Decorating, describes how to construct a tile press for under $100 using basic supplies purchased from the local hardware store. I gave this a whirl, thinking I could save some time (and my ears) over the traditional pressing method. Even though I followed the instructions, I was never able to get the press to work to my satisfaction. The press, it seemed, did not generate enough pressure across the tile to enable the clay to completely fill the mold. My tiles would come out with creases and divots, missing corners or large sections of the design. I also attempted to modify the design a bit, but I never got it working. Perhaps it is the clay I use or my detailed designs, because presses like this are employed successfully by the author. I also believe that the Moravian Tile Works in Bucks County PA uses similar hand presses.
Frank Georgini, in his book Handmade Tiles: Designing, Making, Decorating, describes how to construct a tile press for under $100 using basic supplies purchased from the local hardware store. I gave this a whirl, thinking I could save some time (and my ears) over the traditional pressing method. Even though I followed the instructions, I was never able to get the press to work to my satisfaction. The press, it seemed, did not generate enough pressure across the tile to enable the clay to completely fill the mold. My tiles would come out with creases and divots, missing corners or large sections of the design. I also attempted to modify the design a bit, but I never got it working. Perhaps it is the clay I use or my detailed designs, because presses like this are employed successfully by the author. I also believe that the Moravian Tile Works in Bucks County PA uses similar hand presses.
There are also a number of commercial ceramic presses available for purchase. Some are hand turned, like the North Star Tile Press, while other use hydraulics, like the Peter Pugger Studio Press. The real drawback with these press options is the cost. Due to budget constraints, I probably won’t be purchasing a commercial tile press any time soon, however, I did recently come across another DIY press model that I am dying to try. The Createniks blog post details how to construct a tile press using a hydraulic press purchased inexpensively from Harbor Freight Tools. Maybe this will be my next project!
