"Optimal A4 copy printer paper" typically refers to high-quality paper designed for use in standard A4-sized printers and copiers. Here is a description of what you can expect from such paper A4 paper measures 210 x 297 millimeters or 8.27 x 11.69 inches. It is the standard size for most printers and copiers in countries that use the ISO 216 paper sizing system.Optimal A4 copy printer paper is available in various weights, usually measured in grams per square meter (gsm). Common weights for A4 copy paper range from 60gsm to 120gsm, with 80gsm and 90gsm being the most common choices. Heavier paper tends to be more durable and suitable for double-sided printing.The brightness of A4 copy paper is measured on a scale of 1 to 100, with higher numbers indicating greater brightness. Optimal A4 copy paper often has a brightness rating of 92 or higher, which ensures sharp and clear text and graphics.