Possible Clues:

• Paint in a kindergarten classroom
• Artist's emulsion
• Tone down a painter's medium
• Moderate a style of painting
• One drafted into office takes a long time, painting
• Possibly when contracts were short term or medium
• Painting emulsion with egg yolk
• Tone down a painting technique
• Short-term base artist used to produce painting
• Do casual work with English artist -- he could use it