More and more smartphones, TVs and wearables like Apple's Watch now use OLED displays, but only two companies mass produce them -- Samsung and LG. LG is trying to stay on top of demand by building a new 1.05 trillion won ($900 million) flexible OLED plant in Korea. Starting in 2017, the 6th-gen line will spit out four times as many screens as the current-gen plant thanks to a larger "substrate" sheet size. The plastic-based displays are aimed at smaller next-gen devices that can benefit from the bendability like automotive displays, cellphones and wearables.Most of LG and Samsung's high-end smartphones and smartwatches already use OLED displays (P-OLED and AMOLED, respectively). Some -- like LG's G Flex 2 "banana" phone and the Samsung Galaxy S6 Edge -- specifically take advantage of the flexibility. But other company's products, like the Vivo X5, Oppo R7 and 2nd-gen Motorola Moto X all have OLED-based displays, creating extra demand for the tech. LG said it will eventually build another plant for larger, TV-sized displays that uses the same 6th-gen manufacturing system. Samsung also recently pledged $3.6 billion toward OLED production.