Blenders are fabrics that “read” as solids from a distance but actually have subtle patterns. These patterns are often “cloudy” or organic in nature. The colors on the fabrics are tints and shades of the dominant color.
Quilters like to add blenders to complement favorite prints in their quilt. Examples of these fabrics can be seen below. The first photo shows a wall of blenders. The next photo has a print in the center with a green blender on the left. (The white on the right is also a blender but the pattern is hard to see.) Notice the difference between the green blender and the pink solid. The blender always adds some texture to the mix where a solid is more flat.