A surface including: multiple data pages, wherein each data page includes: multiple optically detectable marks indicating boundaries of the data page; and an array of data cells, wherein a location of an optically detectable mark in a data cell of the array of data cells encodes information and adjacent data pages use different encoding patterns such that an encoded value would be represented by a first pattern of marks on a first data page and the same encoded value would be represented by a second, different pattern of marks on a second data page.