In some cases when you print or copy a document, the text may actually be a shade of gray rather than true black. In these cases, a combination of black and color ink is used to print the text. Also, if you print or copy black-and-white photos, a combination of color ink is used from the color ink cartridge to produce the correct gray scale.
Before you send the document to the printer, try choosing Black & White color option in the printer settings.
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