Superlative form of grainy: most grainy.(adjective)
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Use "grainiest" in a sentence
"When I ate "store" bread (after growing out of the Wonder Bread years and moving to university), I sought out the bag with the densest, grainiest, darkest loaf inside."
"SUZANNE'S CAREER 1963: Also shot in 16mm, this film has the grainiest-looking transfer, but much of the film was shot in low-light interiors and it actually looks quite good, so all is forgiven."
"However the granules are fragile, and readily fragment into finer particles; so having reached its thickest and grainiest, the consistency of a potato-starch sauce rapidly gets both finer and thinner."