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PUSHEN offers multiple types of test drawdown charts, ranging from pure white to various black and white patterns. Made of high-quality non fluorescent paper, without fluorescent whitening agents that affect color testing. Mass production of hundreds of thousands of sheets, with stable quality. The covered cardboard sold has been tested by the East China National Metrology Center (National First-Level Metrology Center) and meets the national standard with guaranteed quality. It is the best choice for laboratory drawdown charts.