The books were produced with paper dust covers up until 1969 . Each one had a unique pattern of squiggly lines at the top but these were not especially practical because they were easy to rip and stain.
12.
Typewriter eraser brushes were necessary for clearing eraser crumbs and paper dust, and using the brush properly was an important element of typewriting skill; if erasure detritus fell into the typewriter, a small buildup could cause the typebars to jam in their narrow supporting grooves.
13.
In times of national anxiety about their country's place in the world _ when Britain is upset about Europe's impending single currency or its anti-British beef policy _ the papers dust off their jingoistic lexicon, trying to buck up Britain by being rude about the French and the Germans.
14.
Besides the usual malfunctions common to laser printers with worn rollers or accumulated paper dust, older IIISi and 4Si printers eventually exhibit a " phantom paper jam . " On longer documents, the printer will stop and report a paper jam, but with no visible reason why the paper wasn't feeding correctly.
