I agree with PodBoy - short of the lamp getting shaken off or the lamp having sharp pointed feet that might scuff the plexi, all you might have to worry about is some odd noise from sympathetic vibration of the lamp. And considering how regularly my cats use my LFM-1 as a stepladder onto the entertainment center (the 20-pound persian can't jump well, so he has to go from LFM-1 to Studio/60 to side cabinet in order to get onto the preferred den vantage point), I would say that the plexi is pretty resilient - their hind claws have left no marks on it that I've found after fifteen months or so of traffic.