The raw main material : Kaolin (50%), quartz (25%), feldspath (25%).
In the “coulage” workshop:
We receive the minerals in powder all ready for use. We mix this powder with water to obtain a liquid paste. This paste is used to fill up the plaster moulds (shaped differently according to the various items). The setting takes from 2 min to 45 min according to the shape and size of each model. When we turn the piece upside down, the excess of liquid runs down and the shape appears. When we take the piece out of the mould, the piece is still wet.
More work has to be done on the pieces, of course, for instance handmade details, depending on the order.
In the “finissage” workshop:
The pieces are cleaned with small lames, sponges and water to take off all the defects remaining on the pieces from the moulds. This procedure has to be done very carefully as the pieces are not baked yet, they are very fragile and easy to break.
The first baking lasts 6 hours and the temperature is 980°C. It is called “phase de dégourdi”. The goal is to deshydrate the pieces, make them porous.
After the pieces are dried workers stamp the pieces with the label “Limoges France” or/and “CC”.
Glazing bath: the same powder is used as in “coulage” but with different proportions in order to obtain the glazing of the piece. The piece is bathed in the email and as it is dehydrated the piece absorbs the email very quickly (1 or 2 seconds). The bottom part (where the piece has to stand) is wiped off so it doesn't stick to the plaque during the next step.
At this step the blue colour characteristic of Limoges Porcelain can be created by adding into the glazing bath a pigment named cobalt blue.
It lasts 6 hours and the temperature rises up to 1400°C. During this step each piece reduces by 14%. Consequently, the moulds for each piece must be created considering this factor.
The main possibilities after this are:
_White porcelain without “emaillage”, it has a mat aspect and is called ‘biscuit’ (bis=2 , cuit= cooked).
_ Porcelain with “emaillage” white.
_ Porcelain with “emaillage” blue.
At this point, the pieces are not porous anymore and are ready for sale or for decoration.
In the decoration workshop:
All the decors have to be baked. These baking lasts 6 hours and the temperature varies between 650°C and 850°C depending on the colors. So each piece can be baked 1 or several more times from the highest temperature to the lowest.
Different types of decors exists:
_Décalcomanie (transfer made by printers) can be put on the porcelain.
> Filet (lines and contours) are made on a “tournette” (disk turning) with a pencil and colours diluted in oil and essence (terebenthine or orange).
> Handmade pencil paintings.
> Incrustation can add relief to the piece.