How do you store your saddle? Many people use saddle racks (middle picture), which press into the panel (underside) of the saddle, leaving grooves (first pic). The more you weigh the saddle down (ie heavy stirrups, girths etc, the worse this can be. This means that instead of a nice smooth bearing surface against the skin of the horse, you have lumps either side.
The panels can be improved with judicious flocking. For the future you can put foam padding onto your saddle racks (third pic), or put plenty of pads between the saddle and the rack. We store all our new and secondhand saddles on poles that fit into the gulley of the saddles.