Manufacturer of Ceramic Bodies and Clays for Modelling

Coloured Natural
Self-hardening Clay


Coloured Natural
Self-hardening Clay

General description and properties​

SIO-2® COLORPLUS is coloured natural self-hardening clay. No firing is necessary. After drying, it achieves a high hardness and solidity. It is a suitable material for development of creative skills and plastic expression. Recommended in handicrafts and professional creative arts, and also suitable for children (from 3 years old).

It has very good modelling plasticity. Its natural clay components give an excellent plasticity to the modelled item and the presence of natural fibres of cellulose allows a secure drying, free of cracks and fissures, even for the large pieces.

Available in 5 bright colours:

All the COLORPLUS clay colours can be mixed, also with the SIO-2 PLUS® clay colours. Therefore, unlimited shades of colour can be easily obtained.

Once dry, the clay can be painted or varnished with any type of paint or varnish. It can be also polished, carved or drilled.

Available in 3 sizes: 500g, 1,5 kg y 5 kg.

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

What makes COLORPLUS clay different?

Compared to natural pottery clays, COLORPLUS clay is available in nice and bright colours and does not need firing. Once dry, the item becomes very solid and hard and can be decorated or varnished. The clay allows creating objects with difficult drying, free of cracks and fissures while drying.

Compared to SIO-2 PLUS® natural clay, COLORPLUS clay displays brighter colours.

In comparison to other air-drying clays, COLORPLUS clay is made of minerals and natural clays, with plasticity noticeable at touch, but especially is recognizable by the lack of smell. In addition, COLORPLUS clay can be thrown on a potter’s wheel.

How to use it
  • To use a cutting wire to slice enough clay to work with (Picture 1).
  • It is recommenced to knead COLORPLUS clay before working with it.
  • If during modelling the clay loses its plasticity, it is enough to slightly wet your hands.
  • The clay is easy to model, using adequate modelling. 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)
  • The colours are easily mixed by hand.
  • 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).
  • To seal two already dry pieces conventional glue can be used. It is not recommended to glue a dry piece to a humid one, because the glue will not hold, as the humid piece shrinks while drying.
  • 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.

How to preserve it
  • Once the container is opened, COLORPLUS clay needs to be wrapped in plastic in order to be preserved
  • Since it contains a minimum of humidity, it can be recovered by wrapping it in a humid cloth.
  • During work interruptions, cover the item with a 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.

  • When finished, leave the item dry to the air
  • Hardness and maximum resistance are obtained after drying at room temperature from 1 to 4 days.
  • With small pieces, drying can be speed up by exposing the item to a manual dryer. In these cases, the time for obtaining a maximum hardness and solidity is reduced to a few minutes.
  • Hardness can be reinforced additionally, by completing the drying in domestic oven at temperatures between 100ºC and 110ºC (180-200ºF).
► While drying, COLORPLUS clay shrinks. The more water contains the clay, the more it shrinks during the drying. When modelling big size pieces or objects with a difficult drying, it is recommended, before modelling, to first leave the clay to dry for a while and then homogenize it by kneading it.

Finishing and decoration
  • Once dry, the item can be polished, carved or drilled, before being painted.
  • It can be decorated with any type of painting, with pencil or marker.
  • Because the surface is not porous, one single layer of painting is enough to obtain all the brightness of the colour.
  • It can also be varnished. The use of the varnish is recommended to highlight the clay bright colour. Using varnish ensures greater durability and allows easier cleaning.
► COLORPLUS clay is not water-resistant. It should not be use for items which will contain water, unless they are protected with waterproof product.


How long COLORPLUS clay takes to dry?

COLORPLUS clay is essentially made of natural clays. Therefore, the speed of drying is the same as the one of the 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).

Do I have to use all the clay once the pack is opened?

If all the clay is not used, it can be kept for another time, keeping the excess in a tightly closed plastic bag. If when using the clay again we notice that it has hardened slightly, it is enough to moisten the fingers before modeling.

Why does COLORPLUS clay stain hands during modeling?

Like any natural clay, COLORPLUS clay stains hands while modelling; however, the effect is more visible because the colours are much more vivid. The colour comes from very fine-sized organic pigments that disappear washing your hands with water.

Synthetic clays in bright colours, do not stain hands because the pigments are chemically included in the product.

COLORPLUS clay can be fired?

Is not recommended to fire COLORPLUS clay. The natural pigments that colour the clay decompose during firing.

Can it be a danger if a child ingests COLORPLUS clay?

Clay is not 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 COLORPLUS clay expire?

All the PLUS 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