在形形色色的案件中，经常遇到对毛笔字的检验，有些犯罪分子利用毛笔字醒目的特点，书写反动标语、反动传单．诬蔑、诽谤他人的大小字报，或为达到绑架敲诈、索取财物的目的，书写恐吓信和敲诈信；在经济、民事等类案件中，常可遇到一些用毛笔书写的契约、合同、借收据及遗嘱 In all kinds of cases, we often encounter the test of calligraphy and writing. Some criminals use the striking characteristics of calligraphy and writing, reactionary slogans and reaction flyers. Slander others, slander the size of others, or in order to achieve the purpose of kidnapping and extorting money, writing intimidation letters and extortion letters; in economic and civil cases, you can often encounter some writing contracts with a brush, a contract, a receipt And wills