Extender is a wonderful medium when applied properly. I find in my travels, however, that students don't know how to properly apply the extender and therefore don't experience the important benefits of using this product.

Why use extender? Extender allows more open time during the layering process, which then gives you more time to blend one value of paint into another and creates a smooth transition between values. Blending lines can be softened using a small mop brush or a clean, dry filbert.

How to apply extender. Use a large, clean, flat brush to apply extender over the entire surface, brushing back and forth until an even sheen is apparent. (Do not mistake this from a wet puddle look.) The purpose of moistening the entire surface rather than just the area where paint is being applied is that the extender dries from the outside in and therefore the larger the area being moistened, the longer it will take to dry. Also this will allow you to work your entire painting at the same time, applying lights and darks to several areas. If an area dries too quickly, the extender can be reapplied in that area.

Heat set between applications. Use a hair dryer to heat set paint. This will prevent it from reactivating or lifting between applications of extender. For further protection between applications, apply a thin layer of Glaze Medium after heat setting.