Singular mechanical bands may come in a variety of width, shapes, intensity and neighborhoods. Those bands are nonperiodical, appear across the sheet (from side to side), and are often wider than 2mm, which makes them noticeable from a normal viewing distance. Massive manual evaluation of mechanical bands is done during the development of new printers, in order to remove the mechanical cause of the bands, and during Print Quality (PQ) tests. In some cases, as in monitoring improvements following a test of a proposed solution, or in the press-release quality tests, the test should be objective and repeatable, qualities that do not exist in human observations. An automatic tool for perceptual evaluation of mechanical bands is, hence, preferable.In this paper, we steady human priorities in singular band evaluation. In particular, we find the human sensitivity function per band width of singular bands, which differs from the wellknown human sensitivity function to wave-length of periodical bands. A main result of our steady is a Mechanical Band Measurement (MBM) tool. The MBM tool rates general mechanical bands in a score that correlates with band severity. We compare the tool's scores to committee evaluations and show that the tools agreement with the committee is better than the agreement between the members of the committee.Singular mechanical bands may come in a variety of width, shapes, intensity and neighborhoods. Those bands are nonperiodical, appear across the sheet (from side to side), and are often wider than 2mm, which makes them noticeable from a normal viewing distance. Massive manual evaluation of mechanical bands is done during the development of new printers, in order to remove the mechanical cause of the bands, and during Print Quality (PQ) tests. In some cases, as in monitoring improvements following a test of a proposed solution, or in the press-release quality tests, the test should be objective and repeatable, qualities that do not exist in human observations. An automatic tool for perceptual evaluation of mechanical bands is, hence, preferable. In this paper, we steady human priorities in singular band evaluation. In particular, we find the human sensitivity function per band width of singular bands, which differs from the wellknown human sensitivity function to wave- length of periodical bands. A main result of our steady is a Mechanical Band Measurement (MBM) tool. The MBM tool rates general mechanical bands in a score that correlates with band severity. We compare the tool's scores to committee evaluations and show that the tools agreement with the committee is better than the agreement between the members of the committee.Singular mechanical bands may come in a variety of width, shapes, intensity and neighborhoods. Those bands are nonperiodical, appear across the sheet (from side to side), and are often wider than 2mm, which makes them noticeable from a normal viewing distance. Massive manual evaluation of mechanical bands is done during the development of new printers, in order to remove the mechanical cause of the bands, and during Print Quality (PQ) tests. In some cases, as in monitoring improvements following a test of a proposed solution, or in the press-release quality tests, the test should be objective and repeatable, qualities that do not exist in human observations. An automatic tool for perceptual evaluation of mechanical bands is, hence, preferable. In this paper, we steady human priorities in singular band evaluation. In particular, we find the human sensitivity function per band width of singular bands, which differs from the wellknown human sensitivity function to wave- length of periodical bands. A main result of our steady is a Mechanical Band Measurement (MBM) tool. The MBM tool rates general mechanical bands in a score that correlates with band severity. We compare the tool's scores to committee evaluations and show that the tools agreement with the committee is better than the agreement between the members of the committee.