Homework 4/11 - painting mediums

 Sue

ACRYLIC

There are many different mediums available for Acrylic paints including ones to extend, thicken, thin, or create a glazing affect. The easiest way to thin Acrylic paint is with water
 Acrylics can be used on a large variety of surfaces, including canvas, paper, wood, degreased leather, brickwork, or anything which is neither greasy nor too glossy. Ideally the surface should be prepped with Gesso.           

The best brushes for acrylics are made with synthetic hairs. Brushes can be cleaned with water and hand soap. Never let paint dry on brushes or you will have to throw them away.

1. Spray and spread- spraying a fine mist of water over a particular portion of the painting then tilting, angling, blowing on or brushing the paint until the desired affect is achieved.
2. Using masking tape to protect an area rather than trying to paint around it.
3. Scumbling - a painting technique for adding a layer of broken, speckled, scratchy color over another color. Bits of the lower layer(s) of color show through the scumbling. The result gives a sense of depth and color variation to an area.

OIL

The binder in oil paint is linseed oil.Linseed oil is also a common thinner for oil paint. Others are walnut oil, Turpentine and Liquin, although Turpentine and Liquin have solvents added that you may want to avoid. Stretched canvas primed with Gesso is the most common surface for oil color.Sable and Bristle hair are the best, but imitation hair brushes can work as well.

1. Fat over Lean – this is the concept of painting thicker (slower drying paint such as straight out of the tube) paint over thinner (faster drying such as thinned with oil or turpentine) paint. Reversing this would cause the thinner paint on top to dry faster and then contract and crack as the paint underneath dries.
2. The build-up technique is a layering process which  involves placing the whites and lightest parts last in thick layers of white-tinted paints or light colors on the top of the painting. 
3. Wet-on-wet – an expert technique in which a painting is done  in one-three days (before the paint begins to stiffen), requires an firm grasp of color theory, and is frequently started with an oil sketch or light underpainting.

WATERCOLOR

The binder for water color is gum Arabic. Watercolor paint is thinned with water.

The best surface is paper specifically made for watercolor painting. Traditionally

the paper is stretched for water color painting.  

Sable hair brushes are recommended, but the synthetic version will work and will  

last longer.

1. Wet-on-wet – simply put, this is applying wet paint to wet paint. In this technique the colors will spread into one another, producing soft edges and blending.
2. Wet-on-dry – This is applying wet paint to dry paint. This   produces sharp   edges to shapes.
3.  Laying a wash - useful for providing a background or for covering a large area. It can either be done in one tone, known as an even, smooth, or flat wash; or gradually getting lighter, known as a graded wash.