Units of paper quantity of 480 sheets, now known as a 'short' ream. Reams of 472 and 516 sheets are still current, but in retail outlets paper is typically sold in reams of 500. As an old UK and US unit, a perfect ream was equal to 516 sheets. Certain types of specialist papers such as tissue paper, greaseproof paper, handmade paper, and blotting paper are still sold (especially in the UK) in 'short' reams of 480 sheets (20 quires of 24 sheets). However, the commercial use of the word 'ream' for quantities of paper other than 500 is now deprecated by such standards
Electronic paper technological advantages. All electronic paper technologies face the following general challenges: Electronic ink can be applied to flexible or rigid materials. For flexible displays, the base requires a thin, flexible material tough enough to withstand considerable wear, such as extremely thin plastic. The method of how the inks are encapsulated and then applied to the substrate is what distinguishes each company from others. These processes are complex and are carefully guarded industry secrets. Nevertheless, making electronic paper is less complex and costly than LCDs. There are many approaches to electronic paper, with many companies developing technology in this area. Other