Tuesday, March 22, 2016

Underglaze pencils and pastels

Underglaze pencils and pastels are a great way to add surface decoration to ceramic pieces in the form of drawings, mark making, or adding simple pops of color! They are applied to bisque fired clay just as you would apply regular pencils or crayons to paper. To start the process you will need.....

1. White Firing Ball Clay.... 100 grams
2. Potash Feldspar.... 50 grams
3. Silica.... 50 grams
4. Macaloid (or bentonite).... 6 grams
5. Mason Stain Colorants*.... 30 grams or less
* Mason Stains come in a wide range of colors, pictured below is an example of some colors. Colors can be purchased through any ceramic/clay website. 1/4 LB should be more than enough to create a 200 gram batch of the mixture, which equals roughly 12 pencils and 12 pastels.

1. scale
2. mixing container / mixing object (palette knife)
3. plaster slab ( to roll out your pencils and crayons out on )
4. rubber rib
NOTE: All these chemicals need to be processed with proper ventilation and a dusk mask!
Once you have obtained all the necessary chemicals and have taken necessary safety precautions, begin by zeroing-out your scale. Measure out all dry chemicals and put into your mixing container. Add water and mix until the mixture is a thick paste. Once you have your paste, spread the mixture with your palette knife onto the plaster slab (like icing a cake!). Once every bit of the mixture is smoothed out, let it dry until it is plastic like and you are able to peel up the sides with your rubber rib.
Once the stained mixture is dry enough to start peeling up the edges, roll the slab up into coils. The coils can very in size depending on preference of pastel or pencil size (Pencils are usually thinner and skinny, like lead. Pastels thick, perfect for coloring). Once rolled into coils, cut out the pencils and pastels into the lengths you need.
The pieces you intend to be the pastels are ready to be laid out and air dried until no longer flexible. The pencils, will need to be fired in the kiln. Once you are finished, they should look like this...

Now, you are ready to use the pencils and pastels! Happy drawing!

They can be used just like regular pencils and pastels, just remember - this must be done on bisque fired clay!

Once you have created your drawing and are happy with your piece, it is ready to be glazed! Because pencils and pastels will smudge, the glaze will need to be sprayed on. Once sprayed, it is ready to fire! Have fun!

  Author: Madison Gibbs

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