Tires with much width or aspect ratios of 65 or lower will need to be balanced in two planes. Thus, you are likely to see weights on both the inner and outer surfaces of the wheels.
Taller tires, aspect ratios 70 and above, can also be balanced internally. Look into DynaBeads and CounterAct beads, as well as DIY balancing with Airsoft beads. I have DynaBeads in my motorcycle tires, Airsoft beads in the 255/85R16 truck tires I mounted at home, and as something of an experiment I put Airsoft beads in the 215/65R16 winter tires on my Crown Vic - even though the bead companies recommend against beads in aspect ratios of 65 and lower.
Winter and summer tires for my 2007 Corolla (currently at 239,000 miles) are 195/65R15 and are balanced in two planes with conventional weights.
The beads in the Crown Vic are OK, though not perfect. I may bump them from 3 oz. apiece to 4.5 oz. the next time I feel like breaking down tires. That's what I have in the light truck tires. The Vic's summer 225/60R16 tires are two plane balanced in the usual manner.