A laminated glazing comprising an SPD ply comprising a suspended particle device having a low light transmission off-state and a high light transmission on-state, at least one interlayer ply comprising an interlayer material, and at least one glazing ply is disclosed. The interlayer material has been dried to a predetermined moisture content to increase the time over which the suspended particle device is switchable between the low light transmission off-state and the high light transmission on-state. Use of a dried interlayer to increase the time over which an SPD film is switchable between a low light transmission off-state and a high light transmission on-state is also disclosed. Additionally a process for producing the aforementioned laminated glazing is disclosed. It has been found that the moisture content of the interlayer material is a factor in determining the switching characteristics over time of an SPD film incorporated into a laminated glazing.