sentences:  Patterns are made to exacting standards of construction, so that they can last for a reasonable length of time, according to the quality grade of the pattern being built, and so that they will repeatably provide a dimensionally acceptable casting.The making of patterns, called patternmaking (sometimes styled pattern-making or pattern making), is a skilled trade that is related to the trades of tool and die making and moldmaking, but also often incorporates elements of fine woodworking.Patternmakers (sometimes styled pattern-makers or pattern makers) learn their skills through apprenticeships and trade schools over many years of experience.