“300 Sandwiches” is about to become a book. The Post’s Page Six reporter Stephanie Smith is going to turn her humorous blog into a book after signing with Random House’s new imprint, Zinc Ink — headed by David Zinczenko and Stephen Perrine.

“Steve and I are both longtime friends of Stephanie from her days covering the magazine business for Women’s Wear Daily,” said Zinczenko, a longtime editor-in-chief of Men’s Health and now consulting for Men’s Fitness through his Galvanized Brands consulting firm. “So when she told us about her romantic, passionate, and very funny quest to make her boyfriend 300 sandwiches, our first reaction was, “That’s a book.”