Regular cleaning prevents build up on the image sensor of materials such as dust, label adhesive, inks and oils which can deteriorate scan quality. Re-calibration will help revert the scanner back to original specifications and resolve most image quality issues.For an average user, we recommend cleaning your scanner about every three months. For heavy users, once a month or even more frequently may be necessary. Generally, the best indicator of a needed cleaning will be the appearance of any black streaks that show up on your scanned document. We recommend recalibrating your scanner first. If this does not improve the quality of your scans, then clean your scanner using the supplied cleaning sheets.