The present invention provides methods and apparatus to encode substrates
(e.g., paper, synthetics, etc.) with information. In one implementation a
method is provided including: receiving data that corresponds to a
two-dimensional signal that encodes plural bits of data; receiving data
that corresponds to a frequency-domain signal, the data corresponding to
a representation in a spatial domain through inverse transforming the
frequency-domain signal; and defining characteristics for an element of a
substrate-making process, the characteristics including at least a
pattern representing the spatial domain representation and the
two-dimensional signal.