Assertion: constancy's idea | /r/HasProperty | workable
Facets:
Source sentences:
text: For example, the idea that you can hold up paint on a brush, palette knife or other device and match it with your subject is in general workable only if you have some way of turning up the illumination on your brush until you can match the brightest highlight on your subject with the tone of your paint, and can keep the illumination at the same level while you compare the other colours.