Hi all, been a lurker here and a subscriber for years. Recently I did work for a hedge funder that had me hanging rare art in his huge foyer. The paintings are extremely valuable and the frames are quite heavy. I told him if I were to do it I would want to do some structural work on his walls so I could use heavy duty fastners to ensure that they were hung without risk and worry for either of us (me mainly LOL). After erecting scaffolding and using ropes and manpower to hoist them I felt secure that the job was done with integrity and I could sleep at night. The designer asked if I could do some work at some of her other clients homes for the same type of work, one of them with plaster walls. Since some of the hangings/leaded mirrors are 100lbs I'd feel more secure going into the studs. Being wallpapered walls it'll be important for me to locate studs with a minimum of disruption to the walls. I don't use studfinders since my experience with them has been poor. I can measure off of electrical boxes assuming that the studs are 16" oc, but I've run into 24" or some have been a bit off, off enough for me to be off from the center of the stud. I'm not comfortable anchoring into the plaster through the lath for the heavier paintings. Any ideas out there to help me locate the studs?