Using sponging to decorate a wall is a perfect way to add an interesting effect to a wall, and the acrylic paint which is the basis for the sponge paint daub can look attractive when combined with a contrasting background color. One of the aspects of sponge painting that many amateurs forget to apply is the glaze which is added to the acrylic paint, and which really makes it pop from the wall. Sponging using an acrylic paint which is not glazed can create a cool effect, but adding a glaze could make your decorating something very special.
The purpose of adding a glaze to your paint is to add a different texture to the wall, which draws the eye towards the sponge effect, and also provides additional contrast with the background paint. There are 2 different ways in which glaze can be added to the paint to change the texture. You can either use a simple plain gaze, or you can use a tinted glaze. The effects of each can be very different, so you should be aware of what you are using before you begin the mix.
This glaze is the sort which can be used in tiling and ceramic making. Glaze paint is often slightly denser than you might find in craft shops so take care that you purchase the right sort before proceeding any further. How much of the plain glaze you add depends upon the extent of the glaze you wish to use with your paint. Mix the glaze in a pot with the paint, ratios can vary between 2 to 4 parts glaze to every 1 part of paint, or even 16 or 20 parts glaze to every 1 part of your paint. The more glaze you apply, the higher the glaze and more intense the shine.
A tinted glaze has an additional effect in that it adds another color to your paint. You must first choose a color which matches that of the paint for the sponge, and the background paint already on the wall. You can create the effect of a color wash by using your darkest color as a base coat, a slightly lighter color for the paint, one part paint to 4 or 5 parts glaze, and then another wash using 1 part of paint to 16 parts glaze. These are overlapped to create a colorwash affect.
You can also create other effects by mixing your glaze with items such as glitter, or confetti. Mix your paints with a strong glaze to paint ratio, and then add a handful or two of glitter at the end of the mixing process. A clear glaze will really show up the effects of the glitter, making it look rather like prehistoric flies trapped in amber, but you can also use a tinted glaze for one wash, which will give the glitter the appearance of being trapped in a balloon or bubble.
If you are using a glaze, you should also consider how to best mix your glaze and paint so that you don't create a childish shiny wall, but without making your glaze bland.