| Most artists apply watercolor over a pencil drawing, but many of O'Keeffe's watercolors have no underdrawing. |
| These often show white underdrawing, probably white chalk, or outlines sketched in thin oil paint, either in white or a slightly darker shade of the ground colour. |
| In removing the uppermost layer of painted plaster from the cut-out chunk of wall, conservators discovered an underlying sinopia or underdrawing. |
| The elements are painted over a ground of thinly whitewashed underdrawing. |
| An examination of sample panels from two earlier Cologne workshops yielded one detailed underdrawing but otherwise only limited outline markings for the figures. |
| Most artists apply watercolor over a pencil drawing, but many of his watercolors have no underdrawing. |
