Not ready to give that expensive painting to a museum but need the tax break? Give away part of it and collect your writeoff. “Museums ask donors to pledge the remainder of the work as a promised gift, though that can be done years or even decades into the future. A donor who gives 25 percent of a $1 million painting to a museum is entitled to a $250,000 tax deduction, and the museum has the right to show the work three months a year. Should a donor wish to give another quarter of a painting three years after an original gift, it will be re-appraised and the tax deduction will reflect the current fair market value of the work, which may have appreciated.”