3-Dimensional dot code for paper storage

A dot code extractor, comprising:

• an extractor configured to convert blocks of dots embedded in two different colors embedded on a printed medium to a digital signal, one of the two different colors is considered to be the primary extraction color and the other of the two different colors is considered to be a secondary extraction color, and the extractor attempts to extract each block from the primary extraction color first and attempts to extract that block from the secondary extraction color only if the attempted extraction of that block from the primary extraction color was unsuccessful, the extractor including;
• a bleed-through elimination module configured to reduce or eliminate effects of bleed-through on extraction of the blocks of dots caused by matter printed on one side of the printed medium bleeding through to the other side on which the blocks of dots are embedded.