Beginning in 1950, GM introduced an improvement in the cargo area of the panel truck and Canopy Express. It now followed the example of the Suburban by using a one piece, 5 ply floor. This replaced the planks that were always used in the pickup.
GM implied this would better seal dirt and dust from an otherwise closed area used to haul merchandise and food products.
The following data and picture is as removed from a 1950 pamphlet announcing new features for that year.