Eizo's FlexScan EV3237 has 31.5'' of 4K goodness
 

Japanese display maker Eizo has added a monster 4K model to its stable. The FlexScan EV3237 spreads its 3840x2160 resolution over a 31.5" diagonal, resulting in a pixel density of 140 PPI. It's based on a "non-glare" IPS panel with 8-bit color reproduction, and it has a 10-bit look-up table that's supposed to smooth gradients.

http://techreport.com/news/26849/eiz...of-4k-goodness