Clay and making
I use two different clays, which to make things easy I refer to as the brown clay and the white clay. This is a very general description, though, as the fired colour of the clay varies quite a bit according to temperature and other factors and the white clay doesn't ever fire white as such. Both clays are stoneware clays, that is they fire to the same temperature, and I do use two because of the colour variations which are then possible.
I throw all my pots on an electric wheel. Although I suffer from back problems, the most comfortable position for me is bent over low so I use a Shimpo Whisper. I love throwing. On a good day, throwing pots is a mind, body and spirit experience, and on a bad day it's an enjoyable challenge of skill. To work at your best I find you need to be feeling well, not suffering from any stress and in an open-minded state. Then you can really "go with the flow" and as you work, the steady rhythm of repeat throwing feeds back a feeling of well-being which can also allow even better pots to be made. Sounds great, doesn't it? Well, it happens, but not all the time. But then, most creative people agree that the day you think you've achieved all your goals is the day you stop creating.
After throwing, some pots are then altered in some way. Heart shaped dishes are formed while on the wheel, oval dishes once the pots are 'leather hard' and animals and other shapes are also sculpted on at the leather hard stage.
Glazes and decorating colours
All my pots are glazed before the pot is fired at all. This is known as "raw glazing" or "once-firing", but the latter is a bit misleading in my case as I do fire lustre pots a second time. Many potters fire first to a lower temperature, creating "biscuit ware" which is then glazed before a second firing. Raw glazing has the advantage of economy of firings but the disadvantage that the pots are much more vulnerable at the glazing stage and there are some problems that only show up in the firing. It's the way I've always worked, though, and wouldn't want to do it any other way.
I add colour using a variety of techniques and materials.
Slips: Slips are basically watered down clay with colouring oxides added. I use three shades of blue slip (which I mix
myself) on the "blue slip" design as well as other occasional pots. Slip is applied to the pot either at the leather hard stage or when the
pots are bone dry.
Underglaze colours: These are bought ready-made and used sparingly to decorate individual pots. I use them as you would expect, under a glaze, but some can also be used over a glaze.
Glazes: I make all my own glazes from recipes either given to me or adapted from other potters' recipes. Glazes for raw glazing need to be different from those applied to biscuit ware and it can take a long time to develop a new glaze. I do use more glazes than some might find necessary, but that's mainly because I love to create different coloured pots.
Colouring glazes: These are also made up as recipes but are usually thicker in consistency and are painted or applied with a sponge stamp, e.g. the blue I use in the blue spotty design.
Oxides: Some oxides are used just diluted in water, e.g. I use cobalt oxide to paint the chicken pots.
All of these methods not only have their own range of colours but are very different in consistency and therefore method of application and I tend to mix and match throughout the range of pots that I make.
Lustres are added as an optional extra stage. I use precious metal lustres and coloured lustres on individual pots and on ranges such as blue lustre, which is decorated with platinum. The lustre, e.g. platinum lustre, comes in a dark, viscous liquid which is painted onto the fired pot. The pot is then fired again to about 800deg C and the liquid is burned off, leaving a very thin layer of platinum behind. This is, as children like to put it, "actual platinum"! It's expensive to buy so I usually use it sparingly, but you will find the occasional animal painted in solid metal lustre.
And finally .... you put them all in a big metal box and subject them to a vast amount of heat over several hours and wait to see what comes out!
My kiln is not very big, about 10.5 cu.ft volume, but an amazing number of pots fit in. I fire by bottled gas and using a reduction firing, where at a certain temperature the atmosphere of the kiln is controlled so that the flame is starved of oxygen and has to get it from the clay. You'll see the result of this as speckles in the glaze and it also alters the actual colours of the glazes or decorating colours. The pots are fired to either 1260deg C or 1300deg C - rather hot! - so are well vitrified and therefore normally impervious to water even when unglazed.
I fire to two different temperatures for different glazes and within those two, a variety of types of pot and glazes is needed to make best use of the heat and colour variation within the kiln, so I tend to make pots for a few months and then have a series of firings over the course of several weeks, culminating in one or two lustre firings. This tends to happen every four to six months, so that new pots are available in batches two or three times a year.
The kiln in action seems a little like a wild animal, apparently tamed but only so long as you know how to treat it. What happens to the flame and the heat inside the kiln is controlled to some extent by the input of gas and air, the position of the shelves in the kiln and the density of the pots on those shelves but this still leaves a big unknown for each pot. The colour of the glaze can be affected by what sort of pots it's next to, what decoration they have on them, how much headroom there is above the pots and many other factors, many of which are outside sensible degrees of control, but (barring really ugly unforeseens) this is what I love about it.
Every pot is unique. The underglaze colours, slips, glazes and decorating colours which were all subject to the variables of their consistency and how much was on the brush or sponge when applied to the pot now have the final magic wand waved over them.
I still find unpacking every kiln load exciting.