UNM - Dept. of Fine Arts.
Prof. Clarence Cruz from Ohkay Owingeh Pueblo
Fall 2018
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collecting earth's pigments

FINDING ROCKS
  • Searching for 'soft' rocks with different color hues.
Basic types and Subclasses
  • Sedimentary rocks 
​​Clastic: mudstones, shales, siltsones, sandstones, conglomerates and beccias, and marl Evaporites: salt rock, carnallite, etc.; Soluble: limestone, dolomite, and gypsum; and Coal.
  • Igneous rocks
​​​Volcanic conglomerates, breccias, and lahar; Basaltic breccia; Piroclastic deposits, volcanic ash, tuff and ignimbrite; and Weathering products of crystalline rocks.
  • Metamorphic rocks
​​Slate, phyllite, schists, quartzite little cemented,Metavolcanic deposits​
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  • When you find a 'good' place - Bless Mother Earth; thank her and spread corn flour, ask her to make good pots with her blessing.
  • Test pigment by wetting the rock and scraping it onto a hard rock - if it yields a colored dust/paste, it's good.
  • Collect different colors in different bags.

making pigments

PIGMENT PASTE
  • Soak the rocks in water for minimum of a week or longer. Each color in a separate container.
  • Depending on the hardness of the rock, follow either of these processes:
  1. Grind/pulverize the rock into small particles with either a pestle and mortar or between smooth flat rocks. Add water to make pastes. 
  2. Break down the rock into a paste in the water by hand.
  • Sieve the paste through small meshes and with water.
  • Collect sieved 'juices' and leave to stand for a couple of weeks or more to settle out - note keep colors separate!
  • After a week or so the pigment settles to the bottom and clear water comes to the top - Pour off the water, leaving a little to keep diluted. 
  • Shake up pigment for use.

MAKING PUKIS

EQUIPMENT:
  • SMOOTH INFLATABLE PLASTIC BALL: Sized to suit the size of bowl you intend to make.
  • PLASTER OF PARIS POWDER: From NM clay or hardware store.
  • 3  X 1/4 gallon PLASTIC BUCKETS:
  1. Holding water
  2. A stand for the ball
  3. Mixing plaster 
  • NEWSPAPER
  • NEEDLE TOOL
  • DUST MASK when dealing with plaster in powder form.
  • LATEX GLOVE
  • TABLE TOP BANDING WHEEL
PROCESS.
  • Set up your workspace, covering the table top and banding wheel with newspaper
  • Check ball is fully inflated, and place on open end of one pot, on top of banding wheel.
  • Have Bucket of water to one side, bucket of plaster powder in front and needle tool, and working hand gloved.
  • Pour water into the power and start mixing immediately. Add more water or powder as necessary. working quickly - aim to get a thick runny paste. Be fairly quick as it starts to thicken quickly.
  • Take handfuls of paste and pour onto top, center of ball. It starts to run down and thicken fairly quickly - keep pouring on top and ensure it drips all around the surface of the ball.
  • With a wetted hand you can smooth the plaster exterior - be careful not to scrape it away.
  • While the plaster is still damp, set the needle tool at an angle to the ball and turn the wheel, engraving a ring around the ball. short of the mid line of the ball. Incise all the way to the ball surface (do not puncture the ball.
  • Then make vertical lines from the ring down the sides of the ball - about 1" distance ( this makes it easier to par away excess plaster)
  • Wait a couple of minutes fro the plaster to form a fairly hard set.
  • pare away lower strips of plaster and leave cap to fully harden.
  • Gently press ball around the  bowl to release it from the plaster.
  • once separated - leave to dry further and sand the edges.

TEST TILES

  • Wedge newly processed clay * see 
  • Work into flat patty using the tortilla technique - or roll with pin to about 1/2" thick.
  • Cut into 4 (or more) square tiles - us an even number to make calculating shrinkage more easy. eg 2 x 2 or 3 x 3 - 10 cm x10cm (100mmx100mm) (makes for easiest % calculations- ie a reduction of 8mm is an 8% shrinkage).
  • Carve name and size on back side - and number each tile for identification.
  • Place a board on top, and leave to air dry for 1 - 2 weeks
  • Sand and polish tiles

yucca paintbrushes

  • Using a native yucca leaf (the Soaptree yucca Yucca elatais native to NM and the States national plant).
  • Cut it into the desired lengths, retaining the point for single brush strokes
  • Chew the end on the back molars to make it malleable and separate the fibers
  • Pull forward through the front teeth to strip the pit, and spit it out..
  • Let it dry and cut it to shape. Remove each side of 'bristles' to get desired width of brush.

color tests

  • Once the tiles are dried, set them up to be treated in different ways:
  • TILE 1: Paint with a base stain red # 1 and burnish, followed by stripes of each different pigment.
  • TILE 2: Paint with a base stain red #2 and burnish, followed by stripes if each different pigment.
  • TILE 3: Burnished un stained tile, followed by stripes if each different pigment. 
  • TILE 4: Un burnished, un stained tile, followed by stripes if each different pigment.

firing the tiles

Picture
1 set metal grid off ground with spacer steel tubes
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As fire ignites - shield tiles from flames. have gaps in shield to maintain air flow below tiles
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allow kindling to ignite and burn up. shield fire from wind gusts
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Surround outer edge with lightly crumpled newspaper, covered with kindling
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cover tiles with metal cover
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Lay tiles, face up over the metal grate
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Put a light cover of kindling over top
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Warm up tiles:Light the paper and keep flames from going directly under tiles.
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surround shield with kindling
Our tiles started to pop immediately they were covered on top and as the fire raged. Maybe they hadn't warmed up enough - got hot too soon or air pockets in clay from lack of needing. Or still damp from slip application.  

color test results:

clay decoration

  • Sketch ideas