Scans are blurry, dull or low resolution

Use 300 dpi for letters, forms and anything you want to search or convert to editable text, and 200 dpi for everyday paperwork you'll email. Use 600 dpi for photos you may print or enlarge, and go higher only for small originals such as stamps or slides, because doubling the dpi roughly quadruples the file size.

Black and white mode, sometimes called line art or text, keeps only pure black and pure white, which makes small text jagged and turns photos and pencil marks into blotches. Use grayscale for documents with shading, pencil or stamps, and color for anything in color.

Settings labelled small file size, high compression or low quality save space by smoothing away detail and adding blocky patches. Choose a higher quality or larger file option, or save as PNG or TIFF instead of JPEG when quality matters more than size.

With the printer off, wipe the glass and the white backing under the lid with a lint-free cloth lightly sprayed with glass cleaner. Fingerprints and haze scatter light and soften the whole image. For feeder scans, also clean the narrow glass strip the feeder reads through.

Most scanners focus on a very thin layer just above the glass, so anything lifting even a few millimeters goes soft. Close the lid fully, and for books press gently on the cover; some lids have hinges that rise for thick items. Don't lean hard on the glass or force a book's spine flat.

Magazine and newspaper pictures are printed as tiny dots that can clash with the scanner and form wavy patterns. Turn on a descreen option if your scan software has one, or scan at a higher resolution and reduce the size afterwards.

Some makers' scan apps include a calibration or color adjustment tool. If colors look wrong on every scan, run it and follow the on-screen steps; otherwise adjust brightness and contrast in the scan settings before scanning.

In the Windows Scan app, click Show more to reveal Color mode and Resolution (DPI), and set them before you click Scan. The defaults may be lower than you need.

The maker's scan software usually adds quality presets, sharpening, descreening, dust removal and color restoration that the basic Windows app lacks. Install it from the maker's official support site.

Open the scan at 100% zoom before judging it. Preview panes and some viewers shrink images on screen, which can make a sharp scan look soft or jagged.

In Image Capture, select your scanner and click Show Details. Set Kind to color, black and white or text as needed, raise Resolution, and choose the file format before scanning.

For the best quality, save as TIFF or PNG. JPEG and compressed PDF trade quality for smaller files, which suits email but not archiving or printing.

Open the file in Preview and choose View > Actual Size to see the real detail before deciding to scan again.