There are a range of materials that can be utilised as a support, but the pet portrait artist has to consider what material is going to provide the longest life-span for their painting. Much will depend on the type of paint being used, oil and acrylic tend to be a more flexible medium so can be applied with reasonable confidence on fabrics that have been properly prepared. More brittle mediums such as tempera, gouache or pastel, require a more rigid support such as prepared boards. Even so, no support is perfect and all will be affected by the atmosphere and chemical changes over time, the craft of the artist is to make sure they use the correct support for the medium they use and if done correctly will produce a picture that will last for thousands of years.
Here is an outline of the typical supports suited to painting.
Processed wood
The most stable of the processed woods and arguably the best support for the artist, is MDF (Medium Density Fibre Board). This is stronger and more stable than other processed woods and so is less likely to warp. The surface is quite smooth though does take ground preparations well.
Natural Wood
Natural wood is a readily available for the artist, but it does have to be well seasoned. Suitable examples will show straight close growth rings which where possible are aligned across its thickness. Wood with knots and sap wood should be avoided. As a general rule hardwood make a better support than softwoods
Linen
Linen is the king of cloths for painting, it has a strong, durable consistency that, if well made, offers a relatively blemish free surface with a fine weave.
Cotton
Cotton costs a lot less than linen and is easier to come by, but it isn’t as durable as linen. The better cloths are heavy (10oz or more) have a close weave and few stubs or knots.
Paper and card
Paper is an ancient product that has it’s origins in China. It is made from vegetable fibres matted together to form a sheet. Western paper was originally formed from linen waste (known as rags) but when cotton came into general use, cotton rags came into use. If made with care using the highest quality materials, paper can have a very long life expectancy, but does tend to be easily damaged. In painting it is tends to be used as a ground for water colour, gouache, tempera, pastel and acrylics. Though, if heavily sized, can be used for oil colours. Only acid-free paper will ever have the chance to go the distance.
Stone
A few types of stone that have been tried as painting supports. Some fine examples have survived from the renaissance. Slate is an obvious choice as it comes in sheet form, but other materials such as marble and onyx may provide more interesting backgrounds that can also be utilised. Stone with a non-absorbant surface will not need preparation, though it is always advisable to wipe down with white spirit before starting.