An optically readable sheet has plural mark spaces and has at least two fiducial marks defining the orientation and scaling of the sheet. A method for reading an optically readable sheet may comprise imaging the sheet and decoding the fiducial marks from the image of the sheet for scaling the image of the sheet and decoding the mark spaces therein. Scaling the image may include comparing the locations of the decoded fiducial marks from the image of the sheet and the predetermined locations of the fiducial marks on the sheet.