What is the PFL Dry-Out Time?

Last updated: 2026-10-29

The PFL Dry-Out Time is the number of minutes a slide takes to return within 2 g of its dry weight after being fully submerged for 60 seconds and hung heel-down at about 22 °C and 50% relative humidity. Lower is faster. It is a method defined by PrintFoot Lab, not an industry standard.

Formula

PFL Dry-Out Time = minutes until (current weight − dry weight) ≤ 2 g

Protocol

Step	What to do
1. Dry weight	Weigh the dry slide on a kitchen scale (0.1 g resolution).
2. Soak	Submerge fully in room-temperature fresh water for 60 seconds.
3. Drain	Lift out and shake once. Hang heel-down from a clip.
4. Weigh	Weigh every 5 minutes.
5. Stop	Stop when the slide is within 2 g of its dry weight. Record the minutes.

Worked example (illustrative)

Dry weight	Weight after soak	Within 2 g at	PFL Dry-Out Time
170.0 g	191.5 g	35 min	35

How to read it

Minutes	Our reading
Under 30	Fast drying
30–90	Moderate
Over 90	Slow; water is held in small cells or absorbed

Room conditions change the result, so compare slides measured on the same day in the same room.