Photos of a series of greenware sculptures I’ve been working on. Thrown and assembled in White st Thomas stoneware.
Dwi di ddewis ysgrifennu post yn y Gymraeg am y tro cyntaf ers i mi gychwyn yn y brifysgol dros flwyddyn yn ôl, i weld sut mae’n teimlo i newid iaith wrth siarad am fy ngwaith.
Des i ar draws casgliad o waith cerameg Katharine Pleydell-Bouverie yn yr amgueddfa ‘Potteries’ yn Stoke, a syrthio mewn cariad hefo’i gwydreddau lludw. Roedd y gwydreddau mewn arlliwiau o las, gwyrdd a llwyd yn dibynnu ar ba fath o bren oedd wedi cael ei losgi. Yn y llyfrgell ffindiais ei rysait gwydredd lludw a chymysgais hwn hefo’r lludw oedd ar gael yn adran cerameg CSAD (dwi angen gofyn o ba goeden daeth hwn) Isod mae’r gwydredd sydd wedi cael ei danio i 1280C mewn gostyngiad.
Rysait gwydredd afloyw syml KPB:
Feldspar potash 40
China clay 10
Ball clay 10
(Mae ychwanegiad o 10 gwarts yn gwneud o’n llai afloyw)
Y canlyniad ydi gwydredd gwyrdd gwelw, naturiol. Fy mwriad yw casglu lludw o gyfres o brennau gwahanol a gweld sut mae’r lliw yn newid hefo bob un. Gallaf hefyd newid y feldspar i roi effaith gwahanol (mae’r post diwethaf yn profi hyn). Dwi ddim yn sicr sut i gasglu’r prennau, gallaf brynu nhw ar-lein ond bydd y prosiect yn fwy personol os gallaf gasglu’r pren fy hun.
Dwi’n gobeithio defnyddio’r gwydreddau yma i addurno’r gyfres o jygiau dwi wedi taflu mewn clai white st Thomas. Gobeithiaf dysgu mwy am danio gostyngiad oherwydd bod y lliwiau yn fwy soffistigedig ac mae’r clai yn troi’n lliw hardd mewn awyrgylch isel mewn ocsigen. Dwi di ddod o hyd i lyfr ‘Katharine Pleydell-Bouverie: a Potter’s Life 1895-1985’ yn y llyfrgell sy’n cynnwys lluniau a ryseitiau gwydreddau wedi gwneud hefo lludw cedrwydd, cnau Ffrengig, drain, rhosyn a.y.b.. i grochenwaith caled. Er bod ei gwaith hi wedi cael ei danio hefo coed tan, dwi’n gobeithio cael effeithiau tebyg hefo tanio odyn nwy.
Thinking about the surface effects I’ve identified I liked in the past I found a Mamo Matt glaze in Jeremy Jernegan’s Dry Glazes handbook and made the following variations:
Original: MC36 (W1)
Potash feldspar 50
Calcined china clay 21
Tin oxide 5
W2 – Replaced feldspar with 50 Soda feldspar
W3 – Replaced feldspar with 50 Nepheline Syenite
B1 – Original recipe with 1% cobalt, 8% black iron and 3% manganese
B2 – Original recipe with 4% black glaze stain
Fired in Reduction to 1280C. It was surprising to see how just changing the feldspars could change the colour so much. The potash gives a brighter, more clinical white than soda while the nepheline syenite gives blushes of pink and orange. The manganese gives a matter, more metallic black than the stain which gave more of a dark green undertone. I like the manganese black glaze (below) a lot because of the oily way it reflects the light without being too shiny. Application is better when poured.
Below is the piece I worked on over the weekend, throwing in sections with white st Thomas then joining them together on the wheel when leather hard. Already you can see a wide ranges of tones of light and shadow and a series of ellipses when looking through the form. I enjoyed the process of making this piece and the way the pieces slotted together like a jigsaw puzzle. The next step is to make more of these composite forms but trying to make them less symmetrical and on a smaller scale (maquette size).
For some reason I find throwing and turning bowls more difficult than other forms. I can never seem to get the thick clay out of the base and they tend to end up with strange ridges. The pearlescent glaze here was supposed to be a gloss white but looks like it needed more than one layer.
Page 132 The Glaze Book – Gloss white 1290C
Potash feldspar 60
Quartz (flint) 15
China clay 5
Layered on top of another glaze the opalescent effect might work but I don’t like how watered down it looks revealing the clay underneath here.
The bowl with the oatmeal glaze is my favourite – it’s got rings of different shades of orange with a subtle texture and green tinging where it’s pooled at the base. I like the detail of the running green glaze around the rim too – a touch of Lucie Rie!
Potash feldspar 45
Quartz (flint) 16
Zirconium silicate 11
China clay 6
Zinc oxide 2
Chrome oxide 1
The green bowl has a pleasant mottled antique green colour – white slip with smooth satin opaque yellow green on top applied to bisque ware. I like the visible brush marks and the colour variation where the thickness is different.
I’ve been invited to sell my work in my local hometown and want the glazes to reflect the colours of the rural landscape of North Wales. These thrown vessels have been painted with the glazes I made at the start of the year as part of the local clay project. The bowl has been pained with a glaze made from a 2:3 ratio of Potash feldspar to my clay while the rounded pot has a 2:1 mixture of Whiting and my clay. It flows very much like an ash glaze but luckily wasn’t too runny that it stuck to the kiln shelf. I’m going to add more whiting and feldspar to these glazes because the colours are much darker than I expected.
Here I’ve tested to see what effects can be had when layering slips and glazes onto ash white stoneware.
- White slip with turquoise glaze on top produces crazing in straight lines underneath a patchy shiny green.
- Reversing the above with the white slip on top creates a dry, textured matte surface which doesn’t flake or peel.
- My favourite – yellow/green glaze with blue slip painted on top forms islands of matte dark blue over a shiny surface with a very painterly effect. I like this rough, uneven texture which might look exciting on a large scale.
- The same as 3 but with turquoise glaze on top – this looks like a painted landscape with lots of variations of blue and hundreds of tiny bubbles encased in the surface.
I expected the slips to run off the surface when fired but the addition of glaze works to stick the raw and bisque fired clays together.
I’m really enjoying the challenge of throwing on the wheel. I feel I’ve come a long way since beginning the course in September – I can now control the clay to a degree and make the shapes I want which is new and exciting for me. Most of my last term was spent practising to throw cylinders which was a struggle because the clay is determined to flare out at the rim (hence why most teachers encourage you not to begin with making bowls).
These mugs are slightly tapered cylinders with pulled handles (attached when the body was too dry – there are cracks at the joint).
To decorate I played with layering a couple of glazes from Stephen Murfitt’s ‘The Glaze Book’ – an opaque yellow green and pale satin grey/green. At the moment I am brushing on glazes and making up small batches (100ml) but this is causing very uneven layers of colour. I might choose a couple of glazes I really like and make up a bigger batch so I can start dipping and get a more even coverage.
I don’t feel I’m very good at harmonising form and decoration. My approach has always been ‘more is more’ but I’m going to challenge myself to spend less time decorating and see if I like the pared-down results.