"Laser Wall" effect?

[Pete McCrea]

Fog Screen anyone?

The OP cannot use smoke, haze, fog or anything that lingers. He can use CO2.

 

Hence why I suggested the Fog screen.

 

From their details:

"The device creates only little humidity, roughly 4-6 litres (1-1,5 gallons) / hour, which equals roughly to the perspiration and breath of a group of some 30-40 people, so it should be no problem at any venue."

 

And Tomo mentions some other points of note.