Term: Block-In

Blocking-in is the first stage of painting in oils or acrylics that follows the preliminary sketch or drawing. This is where areas of flat color are put down to represent the large shapes in the painting. The block-in does not usually deal with edge quality or form, but merely captures patterns and other structural components.

Most block-ins are done quickly to establish the fundamental proportions and areas of color that will be over-painted with highlights, shadows and details. The likeness of the subject should be achieved at this stage, as no amount of  modeling later on can correct poorly drawn shapes. In oils, the blocking-in is done with paint that has been thinned with a medium that is mostly solvent.