Field: Development into 3D

In my tutorial with David last week we discussed colour theory and the way putting colour on the back of flat planes can reflect the light in a halo of that colour around the edges. As an example he suggested I look at the first year fine art project displayed on the third floor – I hadn’t looked closely enough at these to notice the optical effect before but it makes the images pop. I glued some coloured paper to the back of my cardboard cutouts and the result above shows a very subtle halo of green and red light shining behind them. It reminds me of the hazy reflection of light you get on overcast days like the ones we had at Port Eynon. If I manage to make some of these in porcelain paper clay I could glaze the backs to get a similar effect.

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After Laura’s plaster casting workshop I was keen to try printing onto plaster because I hadn’t tried it before and I saw the opportunity to make more slab-like forms which I could assemble as a kind of theatrical scenery. I rolled coils of clay and pressed these onto an inked up plate, creating walls around different sections. Next I poured in plaster to a thickness of about 1cm and reinforced the back with scrim. I mixed up two lots of 2 pints water/plaster so I didn’t have to do the whole plate at once. I should have been much neater with the clay by cutting walls from a slab because I would have had to file down the edges less this way. The resulting sections are a bit too thick – maybe I could have poured the plaster sooner. On the plus side, lots of detail came out from the intaglio plate.
I then set these upright in a bed if plaster (4 pints) which again, was poured a bit late so looks like icing slapped onto a cake with a palette knife. The scene looks a bit naff and reminds me more of a snowscene with ice and glaciers than a beach. I like the idea of placing a second inked up plate onto the drying plaster then hanging up the sections when they’re dry so the print is shown on both sides.

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I also tried using coloured slips and sgarffito on slabs of clay. Inspired by Morgan’s Vicarious Wednesday talk I tried using paper resist stencils but discovered I have very little patience when it comes to decorating. Hopefully the slabs below will fire black and white.

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Slips brushed on White St.T

I’ve also been working on making paperclay for the first time. Porcelain casting slip can’t be used for this purpose so instead I had to use porcelain from a bag. I dried out the clay then ground it to a powder in a pestle and mortar, added water, then let it slake down overnight. In the morning I poured off excess water and soaked the paper pulp (ratio of 1:3 to the clay) for 2 hours before sieving it (60 mesh) to get rid of excess water. I mixed the paper and slip together by hand but the consistency was very lumpy so Matt showed me how to use the glaze mixer which blends the paper pulp into a smooth consistency.

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Sieving the slaked down porcelain before adding paper pulp
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Glaze mixer

I made up an ink with black underglaze, a small amount of borax frit to make it less powdery (about 5% is ideal) and copperplate oil. The powders were sieved through 200 mesh then the oil was added gradually, applied to the plate and rubbed off with scrim the same as with the intaglio ink. This afternoon I built a wall around the plate and poured in the porcelain paperclay slip with the hope it will be dry by tomorrow with the ink printed on. The underglaze should stay on when fired but it will need a transparent glaze to seal it. I’m worried the clay might not dry in time for tomorrow’s assessment so I may try using a heatgun to speed up the process.

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Inking up the plate

Matt Glazes on Porcelain

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These are the same variations on a dolomite matt glaze as in the last glaze post. This time they’ve been fired on porcelain in oxidation 1280C. W2 (with soda feldspar) has the best white result, W1 being shinier and less brightly white while W3 has yellowish undertones. B2 is the exact kind of deep matt black I was looking for too, B1 still having a green tinge in oxidation. I’m either going to start hand building with thrown porcelain sections of covering the stoneware sculptures in porcelain slip to get these glaze results.

Throwing in porcelain

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Nick’s slab built box with my thrown form inside
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Distorting the inside of vessels

I’m throwing in porcelain for the first time. It’s getting easier with practice. At first I found it difficult to knead when it came from the bag but it softens up as you work it. Centering on the wheel is a challenge as it likes to come off, but perhaps this is also because I’m throwing with minimal water. Porcelain is a thirsty clay but using too much water will make it difficult to control so I’ve resorted to throwing with slip instead. I love the tones of light and dark created through these distorted inside forms but how well the light plays on them depends lots on the environment where they’re displayed.

Nick is going to create a plaster mould which we can sit these in and pour porcelain casting slip into to sit them in flat slabs. I found it more difficult to get expressive throwing rings in porcelain so had to use a stick to push them out. Unlike the stoneware bulging and rippling the porcelain wants to hold its form or just collapse completely, there is no middle ground.

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Collaborative drawing

Above are the results of our discussion with ideas for constructing a kind of porcelain igloo or box which you could go inside (or at least put your head inside). We talked about how sound might be distorted as it moves through the twisted vessel forms and how we could use boxed like the one above as bricks to construct a wall you look through. We recorded the discussions so I hope to upload those here soon.

Glaze tests – high firing

Tests no.1 and 2 below are the same Blue grey speckle glaze as seen in the previous post with low firing tests. Here I fired them to 1260C rather than 1060C to find out what happened to earthenware glazes at stoneware temperatures. 1 is the glaze on Buff stoneware clay while 2 is on porcelain. I still don’t like the results but maybe this glaze will look better layered with others.

In contrast I really like the opaque speckled green glaze from Emmanuel Cooper’s ‘Potter’s book of glaze recipes’. It has lots of depth on the Buff stoneware (4) and breaks to a warm orange when applied thinly. I like the celadon colour effect on porcelain too (3).



Opaque speckled green stoneware glaze (1200-1220C)

Clear transparent glaze base:
Standard borax frit                         30
Feldspar                                             25
Calcium borate frit                           5
Ball clay                                             20
Flint                                                    20

with addition of :
Tin oxide                                          5%
Copper carbonate                          1.5%