HP Color LaserJet Enterprise CM4540 MFP series - Manual (Page 122)

Automatic paper sensing (auto-sense mode)
The automatic paper type sensor functions when a tray is configured to the Any Type or plain type
setting.
After it has picked up paper from the tray, the product can detect overhead transparencies, paper
weight, and gloss level.
For more control, select a specific paper type in the job or configure the tray for a specific paper type.
Auto-sense settings
Full sensing (Tray 1 only) For each sheet of paper that it picks up from the tray, the product detects light
paper, plain paper, heavy paper, glossy paper, tough paper, and transparencies.
Expanded sensing
NOTE: This is the default setting for all
trays.
For the first few sheets of paper that it picks up from the tray, the product detects
light paper, plain paper, heavy paper, glossy paper, tough paper, and
transparencies. The product assumes the rest of the pages are of the same type.
Transparency only The product distinguishes between transparencies and non-transparencies. This
setting provides the fastest printing, but for some paper types it might reduce print
quality.
102 Chapter 6 Paper and print media ENWW