Manufacturer of Ceramic Bodies and Clays for Modelling

Natural Pottery Clay


Natural Pottery Clay

General description and properties

SIO-2® ARGILA is 100% natural pottery clay. Easy and pleasant to work with. Ideal for modelling, sculpturing and the potter's wheel. It is an educational material adequate for development of creativity. Suitable for children (from 3 years old) and is also recommended for use in creative and decorative arts, and in many other cases, when a natural clay is required.

Its plasticity is well balanced in order to achieve best results during the modelling, drying and firing.

 Available in 2 naturals colours:

After finishing the desired piece, let it dry and then it is recommended to fire it in a kiln (between 970 and 1050ºC) and decorate it with ceramic glaze.

SIO-2 ARGILA clay is available in 3 sizes (1.5 kg, 5 kg y 12.5 kg). The grog version is only available in 10 kg. Grog confers to clay a very interesting textured surface (not flat) which, in turn, provides a set of suitable properties for the design of pieces in complex drying situations, thus avoiding the creation of deformations and cracks

The product conforms to the European regulation EN-71 and to USA regulation (seal AP non toxic product). It does not contain food allergens.

What makes SIO-2® ARGILA clay different?

Compared to other clays, the SIO-2 ARGILA is a very pure and finely ground clay and, in the case of the 1.5 kg format, presented in a practical vacuum single packaging. Its formulation is highly compensated to obtain the best performance during modeling, drying and firing. The raw color persists after firing. Its behavior with the ceramic glazes of the market is exceptional.

Compared to others ceramic bodies or synthetical clays, SIO-2 ARGILA is a 100% natural product, composed only of clay and water, which confers an extraordinary touch. It does not smell and does not leave any substance in the hands.

How to use it
  • To use a cutting wire to slice enough clay to work with (Picture 1).
  • It is recommenced to knead the clay before working with it
  • If during modelling the clay loses its plasticity, it is enough to slightly wet your hands.
  • It is very easy to model. It can also be moulded (we recommend plaster’s moulds) and thrown in a potter’s wheel.
  • To get an even surface, use a wooden roller and 2 pieces of wood of the same thickness (Picture 2).
  • The large wire-loop toll helps to extract large pieces of clay and give shape to the working piece; for example, a bowl (Picture 3)
  • The double-face wire-loop tool is used to remove the traces of clay and smooth over details (Picture 4)
  • To seal two different pieces of clay, mark them with a spatula or a die (Picture 5), and then, using a paintbrush, moisten them with slurry (clay mixed previously with water until a liquid texture is obtained). When pieces are united to form an angle, in order to glue them, it is better to make a noodle of clay along the angle, then to press and define the angle with a spatula (Picture 6).
  • The wooden rib helps to eliminate small imperfections on flat surfaces (Picture 7).
  • The metallic rib is used to eliminate small imperfections on curve surfaces (Picture 8)
  • To polish and smooth the piece, use a damp sponge (Picture 9).
  • For modelling hollow items, flexible supports can be used.
► If clay is used over inside rigid surfaces (of metal, plastic or wood), it is recommended to cover the surface with a sheet of paper or fabric to help the shrinkage of the clay when drying and avoid the appearance of cracks and fissures.

► When uniting two parts of clay, make sure that both are equally humid (hard). If not the softer one will shrink more while drying and will detach from the dryer one.

How to preserve it
  • Once the pack is opened, the clay needs to be wrapped in plastic in order to be preserved.If the clay dries completely, it can be recovered by mixing it with water.
  • During work interruptions, cover the item with plastic or a humid cloth.
► Keep the clay in a cool place and avoid high temperatures. Do not store at temperatures lower than 0ºC (32 F). If freezes, it loses its properties.

  • Once the piece is completed, leave it to dry, avoiding any direct sources of heat or air currents. Slower drying allows avoiding the appearance of cracks and fissures. It is recommended to leave the item to dry on top of porous surface (of paper, wood, porous ceramics, mould or fabric).
  • If it is a very large or solidified piece, it is recommended to slow down drying by covering the piece with plastic, while leaving only a small opening, in order to slow the evacuation of the humidity.
  • Pieces that are completely flat (plates or tiles), should be dried leaving on top a flat weight. It will avoid the piece bends or cracks from inside, which occurs if it is dried quickly.
  • Drying at room temperature takes from 1 to 4 days, depending of the size and the environment conditions (see the FAQ’s).
  • Use SIO-2 ARGILA with grog in case of pieces with difficult drying.
► While drying, SIO-2 ARGILA clay shrinks. The more water contains the clay, the more it shrinks during the drying.

  • Once dry, the piece can be polished, carved or drilled, before firing.

  • Fire SIO-2 ARGILA clay in a kiln at the following optimal temperatures: 1000ºC (1832ºF, cone 06) for the red colour, and 1050ºC (1922ºF, cone 04) for the white.
  • During firing, the item will reduce its dimensions, due to the ceramic firing shrinkage.
► For very large or solidified pieces, it is recommended to make a slow pre-firing at temperatures between 150 and 200ºC (300-400ºF), leaving the door of the kiln slightly open (not hermetically closed). It will help the full evacuation of the humidity while drying. It is recommended SIO-2 ARGILA with grog.

Glazing and decoration
  • SIO-2 ARGILA clay interacts very well with the conventional ceramic glazes. We recommend glazing after firing (twice firing). The best firing temperature for glazing is usually indicated by the glaze manufacturer. For white clay, it is advisable to use alkaline glazes to prevent the white from darkening.
  • We recommend the use of specialized literature for techniques and tips on how to use ceramic glazes.


How long SIO-2 ARGILA clay takes to dry?

The speed of drying is the same as other natural pottery clays (from 1 to 4 days), and will depend on the item size, on its shape and on the ambient drying conditions (mostly temperature and ventilation).

Is it necessary firing SIO-2 ARGILA clay?

If the ultimate goal when using the clay SIO-2 ARGILA is to obtain a long-lasting piece (decorated or not), we recommend firing it in a ceramic kiln, as indicated in the paragraph about how to use it. Nevertheless, the clay SIO-2 ARGILA has multiple applications, and especially because of its texture and plasticity, is an ideal material for modelling and sculpturing.

What is the difference between SIO-2 ARGILA and air-drying clays?

SIO-2  ARGILA clay is the ideal material for creating pieces, using modelling, potter’s wheel and moulding techniques. In order to conserve a long-lasting item, the piece needs firing in a ceramic kiln and then it can be decorated using conventional commercial glazes. It is, in fact, a professional potter’s clay. When a kiln is not available, it is better to use air-drying clays, such as SIO-2 PLUS® or SIO-2® COLORPLUS, which become very hard and solid, once dried, and can later be decorated with any paint or varnish.

What is grog and what is it using for?

Grog is clay calcined at 1450ºC and grounded. It is used to stabilize the clay during drying and firing. The large particle size helps compaction of clay, preventing cracks and helping degassing while firing. Chamotte is used instead of common sand because its ceramic behavior is very similar to clay itself, because, in fact, it is pre-calcined clay (fired), so that no dimensional stresses are generated inside the piece during the entire firing process (heating and cooling).

Can it be a danger if a child ingests SIO-2 ARGILA clay?

Clay is not a food. In case of accidental ingestion, it is a non toxic product, in accordance with the European regulation EN-71 and the USA regulation (seal AP non toxic product). It does not contain gluten or other food allergens. Clay is not suitable for children under 3 years of age because accidental ingestion could cause drowning.

Does SIO-2 ARGILA clay expire?

All the SIO-2 ARGILA clay sizes and packs remain unalterable in its original packaging for a minimum period of two years.

Safety regulation

Material Safety Data Sheet is available upon demand.
T. +34 93 777 23 44 | info@sio-2.com
T. +34 93 777 23 44 | info@sio-2.com