We typically try to print in our standard books sizes - 6 x 9 (Portrait or Landscape), 8.5 x11 (Portrait or Landscape), 8.5 x 8.5 and 12 x 12 - as they are less expensive to print. But if needed, we are able to print custom sized books from 4 x 4 to 12 x 12 for orders of 50 or more books.