It’s official! President Obama on Thursday nominated his current chief of staff, Jack Lew, to be the next secretary of Treasury. Lew would replace Timothy Geithner, who Obama said “will go down as one of our finest secretaries of the Treasury.” Officials close to the process said Lew was the only person Obama seriously considered for the position, and Lew’s time as budget director under former president Clinton—when there were three years of budget surpluses—was considered key in Obama’s decision. Obama also got in a dig about Lew’s signature, which has been widely received as fairly loopy, joking that he considered “rescinding the nomination” at the news. Lew, for his part, joked that he and Geithner “share a common challenge in penmanship.”