Blenders and burnishers are used to blend colored pencils.
Most blenders come in a pencil shape, one exception being Brush and Pencil's powder blender which is covered further down the page. They are used to add brilliance and a can add a gloss finish to make colored pencil artwork look more painterly. They can also be used as a water-resist. Most companies create a pencil that combines the blending and burnishing capabilities. Derwent has one pencil for each.
Blending and burnishing are not the same. Blending mixes and unifies the color and can crush the paper's tooth if done with too much pressure. Burnishing intentionally crushes the tooth of the paper creating a slick surface. The slick surface adds a gloss finish.
This blender works well with most colored pencils, especially oil-based pencils.
The hexagonal Full Blender is not encased in wood so you can use it to blend larger areas or sharpen it to a point for detailed work. It is a colorless oil-wax medium for blending and intensifying colors. It combines the abilities of a blender and a burnisher.
The Prismacolor Colorless Blender can be used to achieve a blended look or soften edges.
The Derwent Burnisher and Blender are two separate items that are sold as a set. The burnisher is a hard, colorless pencil that brings a shine to your finished piece. The blender is a softer pencil used to blend colors together and to intensify the color. They can be used individually or together in the same piece.
Brush and Pencil Colored Pencil Powder Blender is an archival, dry lubricant that very easily blends colored pencil. It eliminates the need for solvents (although they can still be used with it). It does not add a gloss finish like blender pencils.
It is applied with a sponge applicator or a brush on rigid, toothy surfaces like sanded paper, pastelmat, or gessoed paper. It works better with oil-based colored pencils, but can be used with wax-based also. You can layer different colors on top of powdered blender by using a workable fixative if you don't want the colors to blend. When using powdered blender, it is best practice to seal your work with a final fixative.