As he opens up to the press in advance of the dedication of his presidential library, former president George W. Bush also is talking about his most interesting recent work -- oil painting.

Two self-portraits of the ex-president, one in the bathtub and one in the shower, became public after a hacker released copies of Bush family e-mails. In an interview with ABC's "Nightline" on Wednesday, Bush was happy to talk about his art.

"By the way that's not that easy to paint, water hitting water you know, and the perspective," he said of a painting in which he stares at his toes in the bathtub. "It may reflect my precocious nature, me painting myself in the bathtub and the shower."

Bush does not have delusions of artistic grandeur, acknowledging that "the signature is more valuable than the painting." He joked that "a lot of people" were amazed that he could paint.

"I love to paint, painting has changed my life in an unbelievably positive way," he said. "I look at colors differently, I see shadow."

In an interview with CBS' Charlie Rose Thursday morning, Bush showed what he meant by analyzing the host's tie (at about 5:45 in this clip):

He spends two or three hours a day painting, he said.