Artist brushes come in a wide range of sizes, shapes and materials.  Knowing how a brush is made and how the different materials affect the use of the brush can help you to make an informed choice.
 
The artist brush is made up of 3 parts.
 
1.  The Tuft which can be natural hair of synthetic fibres.  The tuft holds and applies the paint.
 
2.  The Ferrule which is the metal part that holds the tuft to the handle.
 
3.  The Handle - a good quality handle is made of hardwood.  Artist brushes can have either short or long handles.  Long handles are for working on a verticle surface when you would be standing further away from the painting.  Short handles are more suited to close up work.
 
The tuft can have soft, medium or stiff hairs -
 
Soft, this is best used with thin paints for blending and glazing.  It gives more control and has a fine point or edge.
 
Medium, this will hold its shape and usually holds more paint.  It is good for painting with medium to thick paints.
 
Stiff, or bristle type brushes, that allow you to push and move thicker paints.  These are especially useful when painting on canvas.
 
Natural hair brushes are often made from sable.  This is a high quality (and high price) brush that is very good for using with watercolours.  However there are also artist brushes that use other natural hairs like squirrel hair, ox hair, goat hair and bristle (which is from the ear of a pig).
 
Synthetic brushes are usually less expensive than natural hair ones.  Synthetic artist brushes are easier to clean as the cell structure of the hairs is smoother than the natural hair.  Synthetic brushes are usually more durable and can be used with watercolours, acrylics and oils.  Synthetic bristle tends to soften a bit in water.
 
*Nylon brushes are the best for acrylics.  They can be kept wet so that the paint doesn't dry in the brush and ruin it.*
 
The Size System
 
The number on the brush is determined by the diameter of the tuft and by the length of the hair.  Most manufacturers use the same standards.
 
For example a size 2 round brush's tuft is 3/32 inches in diameter and has a 7/16 inches hair length.
 
The size of brush you chose is usually a personal preference that comes with experience.  Initially chose a size to suit the painting surface you are using.  A large canvas probably means a bigger size of brush, at least until you get to the detail.
 
Brush Shapes
 
As if that wasn't enough choice, there is also a range of shapes of artist's brushes.
 
Pointed, round brushes - good for highlights and applying smooth paints.
 
Flat, square brushes - good for covering large areas and tree trunks.
'Bright' are shorter versions of a flat which gives more control and is good with thick paints.
 
Filberts (flat brushes with a curved end) - good for hiding brush strokes
 
Riggers or Liners - round brush with long hair shaped to a square tip - good for lettering and detail
 
Fan brush (flat brush with a curved end) - good for grass, clouds, foliage and blending
 
2 Main Brush 'Types'
 
There are two main brush types and your choice will depend on the thickness of the paint you are using.
 
Water absorbing and releasing brushes - including sable and synthetic equivalents.  These absorb the water (and paint), hold it in the body of the tuft and release it through the brush tip.  This type of brush is good with thin, fluid paint.
 
Paste brushes - like hog bristle and the synthetic equivalents.  These brushes hold the paint in the tip.  Good with thicker paints.
 
Buying Brushes
 
Always buy good quality brushes.  Cheap, poor quality brushes lose their hair and the ferrules will loosen on the handle.
 
Surprisingly putting the brush head onto a handle gives a company the right to say that they made the brush!
 
Do You Want to Learn to Acrylic Paint?
 
Visit my eBay store Learn and Do to find out about The Acrylic Painting Course.  This step-by-step painting course shows all the stages to completing 12 pictures.  It is designed so that you learn a range of painting techniques while you are painting the pictures!  An ideal course for beginners and anyone new to acrylic paints.