Fair winds are blowing; the stars are aligned; good omens prevail; and I am finally ready, at long last, to complete Part 2 of the Celtic Number and Alphabet post begun with Carving Plaster back in October 2013! Congratulations are due, or perhaps admonishments, since I completed the tile sets a year or more ago. Be that as it may, I am sure the world is just dying for instructions on my knot letters. So, without further ado, on to the how-tos!
In my first post of the Celtic Number and Alphabet series, I discussed carving directly into a plaster blank to create master molds for the number tiles. For the alphabet tiles, I used a different technique: I first created a tile from a slab of clay, and then cast it in plaster to create a master mold.
Pressed Alphabet Knot Tiles with high-relief, carved design.
Project:
Carving Tiles in Clay
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Materials:
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Tools for creating the tile: template, sponge, clay knife, X-acto knife, ball tool, rubber rib, carving / smoothing tools.
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Step 1: Template Prep
♦ Create a template for the tile design.
Knot Letter A template centered on a piece of clay (paper with printed design).
In Part 1 of the post (Carving Plaster), I spoke more in depth about creating a template, so I will try not to repeat myself here, but instead point out a few observations, mainly concerning materials for the template.
For my knot letters I printed the template out on a sheet of paper, and used that directly on the clay to trace the design onto the surface. However, as the moisture from the clay transfers to the paper, the paper starts to wrinkle, stick to the clay and rip when traced. Annoying. Eh, just deal with it, I thought, and I did for a while.
I then had the brilliant idea to cover the back of my paper template in clear contact paper, hopefully protecting it from the moisture in the clay and keeping it dry, flat and more manageable. It worked! But, the contact paper also made the template much thicker and more difficult to trace. I found that I had to press significantly harder in order to leave an impression in the clay, and the tracings were still faint and difficult to discern, especially for the fine and intricate details of my knot designs. Passable, but not perfect.
Finally, there is always the option of tracing the design onto a piece of thin plastic first (as mentioned in a previous post, I have used plastic from a disposable drop-cloth for templates). The plastic works well with the clay since it does not lose consistency with moisture, and is thin enough that the impressions from the tracing tool are legible. However, this method does require a bit more time expenditure, as the design must be traced twice: once onto the plastic and once onto the clay.
The choice of template material is up to you!
For my knot letters I printed the template out on a sheet of paper, and used that directly on the clay to trace the design onto the surface. However, as the moisture from the clay transfers to the paper, the paper starts to wrinkle, stick to the clay and rip when traced. Annoying. Eh, just deal with it, I thought, and I did for a while.
I then had the brilliant idea to cover the back of my paper template in clear contact paper, hopefully protecting it from the moisture in the clay and keeping it dry, flat and more manageable. It worked! But, the contact paper also made the template much thicker and more difficult to trace. I found that I had to press significantly harder in order to leave an impression in the clay, and the tracings were still faint and difficult to discern, especially for the fine and intricate details of my knot designs. Passable, but not perfect.
Finally, there is always the option of tracing the design onto a piece of thin plastic first (as mentioned in a previous post, I have used plastic from a disposable drop-cloth for templates). The plastic works well with the clay since it does not lose consistency with moisture, and is thin enough that the impressions from the tracing tool are legible. However, this method does require a bit more time expenditure, as the design must be traced twice: once onto the plastic and once onto the clay.
The choice of template material is up to you!
Step 2: Rolling a Slab
Transferring the design to the clay using a ball tool.
♦ Roll out a slab approximately 1/16" thick.
I am sure at this point you are thinking, “Wow, that’s a pretty thin tile!” And, it would be, if that were going to be the final thickness. But, please, let me explain myself!
My knot numbers turned out fairly well, but I still though the final product could be improved a bit. So, I decided that I wanted the knots on my letter tiles to be higher in relief. I could have accomplished this by rolling out a slab the thickness of my final tile, and carving the design into the clay. I admit, this would have worked.
But, my meticulous side commandeered my brain, and I felt compelled to ensure that the heights of all the knots in each alphabet tile were consistent. I know my eyes can sometimes deceive me when judging exactness, especially from tile to tile, so I devised a better solution than the straightforward carving.
Spoiler alert (for those too impatient to read the next couple steps): I carved the design through the 1/16” thick slab, and then placed the 1/16” slab onto a thicker slab to form the full tile. A little unsure of what I mean? Watch and learn!
I am sure at this point you are thinking, “Wow, that’s a pretty thin tile!” And, it would be, if that were going to be the final thickness. But, please, let me explain myself!
My knot numbers turned out fairly well, but I still though the final product could be improved a bit. So, I decided that I wanted the knots on my letter tiles to be higher in relief. I could have accomplished this by rolling out a slab the thickness of my final tile, and carving the design into the clay. I admit, this would have worked.
But, my meticulous side commandeered my brain, and I felt compelled to ensure that the heights of all the knots in each alphabet tile were consistent. I know my eyes can sometimes deceive me when judging exactness, especially from tile to tile, so I devised a better solution than the straightforward carving.
Spoiler alert (for those too impatient to read the next couple steps): I carved the design through the 1/16” thick slab, and then placed the 1/16” slab onto a thicker slab to form the full tile. A little unsure of what I mean? Watch and learn!
Tip: I use Standard Clay #213 Porcelain for carving my tile. While for the most part I use a grogged clay for actually pressing the tiles, a finer clay like porcelain will allow for more detailed carving, more regular cuts and is easier to smooth.
Step 3: Transferring the Design
Transferred design on a slab of clay.
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♦ Place the template onto the slab, and trace the design using a ball tool or other similar implement.
Basically straightforward. Sometimes, once the design has been traced, I realize that a line here or there is a bit faint, or I somehow missed tracing a section. I compare the design on the clay to the template, and go back with a ball tool to “darken” any ambiguous spots. Tip: Placing a piece of newsprint between the slab and your work surface before beginning to trace and cut will prevent the piece from sticking to the work surface, and it will be much easier to move in the steps to come. |
Step 4: Carving the Design
Cutting out the design with an X-acto knife.
♦ Using a small-tipped, easily maneuverable knife (I chose and X-acto craft knife), cut out the negative spaces from the design.
And, color me silly for choosing an intricate design with tons of tiny pieces! Cut all the way through the slab to remove the background pieces of the design. The fine tip of the X-acto knife can more easily excise the tight corners of my design than a larger clay knife, and leaves less material for clean-up later.
Once the design is cut out, the piece is going to be very flimsy. Therefore, I leave a lot of excess clay around the border instead of cutting it away right at the beginning.
Tip: Keep a spray bottle of water handy. Since the clay is so thin, it loses moisture quickly, especially with a complicated design like a Celtic knot that takes a while to complete. If the clay becomes too dry to work, just give it a little spray and wait a minute for the water to permeate through the clay.
And, color me silly for choosing an intricate design with tons of tiny pieces! Cut all the way through the slab to remove the background pieces of the design. The fine tip of the X-acto knife can more easily excise the tight corners of my design than a larger clay knife, and leaves less material for clean-up later.
Once the design is cut out, the piece is going to be very flimsy. Therefore, I leave a lot of excess clay around the border instead of cutting it away right at the beginning.
Tip: Keep a spray bottle of water handy. Since the clay is so thin, it loses moisture quickly, especially with a complicated design like a Celtic knot that takes a while to complete. If the clay becomes too dry to work, just give it a little spray and wait a minute for the water to permeate through the clay.
Step 5: Cleaning
♦ Using fine-tipped tools, and damp sponge and your fingers, smooth the edges and tops of the design.
My least favorite part of the process by far – ah, the drudgery of cleaning a piece sponge-full of minute crevices! But, enough of my complaining.
My go-to tools for carving, as well as cleaning small spaces, are my trusty metal dental tools. The one I specifically prefer has a small spade-shaped head with a rounded tip and a convex back – the tip smooths corners, and the back tackles the hard-to-reach edges of the design. I then use my fingers and a damp sponge to clean up the surface of the design.
My least favorite part of the process by far – ah, the drudgery of cleaning a piece sponge-full of minute crevices! But, enough of my complaining.
My go-to tools for carving, as well as cleaning small spaces, are my trusty metal dental tools. The one I specifically prefer has a small spade-shaped head with a rounded tip and a convex back – the tip smooths corners, and the back tackles the hard-to-reach edges of the design. I then use my fingers and a damp sponge to clean up the surface of the design.
Smoothing the edges of the cuts.
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Smoothed edges and dividing line details.
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Step 6: Adding Accents
♦ Use carving or stamping tools to add accents to the design.
My knot design does not need too many extra details. With a ball tool I carve the overlapping demarcations between the knot lines, but that’s about it. If your design requires more accents, by all means, accent away!
My knot design does not need too many extra details. With a ball tool I carve the overlapping demarcations between the knot lines, but that’s about it. If your design requires more accents, by all means, accent away!
Step 7: Rolling a Second Slab
7/16″ thick slab for the base of the tile, placed on the bottom board of the plaster casting assembly.
♦ Roll out a second slab of clay to serve as the base for the tile.
The dimensions of your finished tile will determine the thickness of this second slab. I want my finished tile to be ½” thick. Since the top of my tile (the design I previously cut out of the first slab) is 1/16”, I roll out a slab for the base of the tile that is about 7/16”. I also make sure I have some wiggle room in the length and width of the slab. My final alphabet tile will be approximately 3.75” wide by 5” high (my template is a bit larger to account for shrinkage during drying and firing). I roll the base slab larger than my template, with an inch or more of margin on all sides. I have found that the extra clay makes assembly easier.
For my knot letter tiles, I leave the texture from the canvas of the slab roller on the surface of my base slab to add a bit of interest to the tile. As a result the background of the final tile has a light texture behind the knot design. Smooth the surface of the clay to remove the texture if preferred.
The dimensions of your finished tile will determine the thickness of this second slab. I want my finished tile to be ½” thick. Since the top of my tile (the design I previously cut out of the first slab) is 1/16”, I roll out a slab for the base of the tile that is about 7/16”. I also make sure I have some wiggle room in the length and width of the slab. My final alphabet tile will be approximately 3.75” wide by 5” high (my template is a bit larger to account for shrinkage during drying and firing). I roll the base slab larger than my template, with an inch or more of margin on all sides. I have found that the extra clay makes assembly easier.
For my knot letter tiles, I leave the texture from the canvas of the slab roller on the surface of my base slab to add a bit of interest to the tile. As a result the background of the final tile has a light texture behind the knot design. Smooth the surface of the clay to remove the texture if preferred.
Tip: I place my base slab directly onto the glass surface of the bottom of my plaster casting assembly. This way I can assemble the tile in place and will not have to move it a second time when I am ready to create my master mold.
Step 8: Assembling the Tile
♦ Place the design slab on top of the base slab.
Hey, Mr. Hare, slow down there! But, seriously, have a care when moving the top piece, as it is quite fragile at this point due to its lace-like construction. After spending a few hours perfecting my design, I have come to this step only to have the insidiously thin piece of clay warp or even break as I attempted to move it.
I have found that the clay holds its shape a bit better if it has dried just a tad. But, a word of caution, don’t allow the clay to dry too much! The clay will become difficult to cut in the final steps, and it will also become smaller than your original design dimensions since clay shrinks as it dries. Find a happy moisture medium!
Make any final touch-ups to the top piece, since moving the tile sometimes creates blemishes in the design.
Hey, Mr. Hare, slow down there! But, seriously, have a care when moving the top piece, as it is quite fragile at this point due to its lace-like construction. After spending a few hours perfecting my design, I have come to this step only to have the insidiously thin piece of clay warp or even break as I attempted to move it.
I have found that the clay holds its shape a bit better if it has dried just a tad. But, a word of caution, don’t allow the clay to dry too much! The clay will become difficult to cut in the final steps, and it will also become smaller than your original design dimensions since clay shrinks as it dries. Find a happy moisture medium!
Make any final touch-ups to the top piece, since moving the tile sometimes creates blemishes in the design.
Tip: Spraying the top of the base slab with a little water will help the top piece to stick to the base.
The carved design placed on top of the base slab.
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Trimming the edges of the tile.
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♦ Cut out the final tile.
Using a straight edge and a clay knife (re-purposed paring knife), I cut the excess clay from each edge. If your border lines have become a bit faint, or if you believe the drying of the top design piece has altered the dimensions of your tile, place the original template back over the design and retrace the border lines.
♦ Smooth the edges of the tile with a damp sponge to round the corners and remove any marks left by the knife.
Using a straight edge and a clay knife (re-purposed paring knife), I cut the excess clay from each edge. If your border lines have become a bit faint, or if you believe the drying of the top design piece has altered the dimensions of your tile, place the original template back over the design and retrace the border lines.
♦ Smooth the edges of the tile with a damp sponge to round the corners and remove any marks left by the knife.
Smoothing and rounding the edges of the tile with a damp sponge.
Step 9: Making the Master Mold
The final tile ready for molding.
♦ Cast the tile in plaster to form a Master Mold.
I cover the basics of plaster casting in another post (Meet My Friend, Plaster: Making a Plaster Press Mold), so I will not go into depth about the process here. However, the master mold can be used to create a pressing mold: press a tile from the master mold, and cast that tile in plaster. You will use the pressing mold, and not the master mold, to make subsequent tiles. This way, if your pressing mold breaks, you can cast another pressing mold from the master mold.
Alphabet Knot Tiles
