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A photographic print that undergoes flashing can qualify for the “Guaranteed TCQ” label.
Flashing is a darkroom technique in which the undeveloped paper (on which the photograph will later be printed) is exposed to a small amount of blank white light.
The purpose of “flashing” paper is to give the paper a “head start” in exposure so that when the paper is subsequently exposed to the negative, highlight (bright) areas of the photograph will show pictorial detail rather than printing as pure white.
A web search for flashing paper darkroom will provide more detailed information on the technique.