Where do you cane her?

On her chest

"Back on the post, Imogen." You tell her, and she moves to replace her hands. You give her ass a sharp smack, and she yelps, her whole body stiffening in pain - much of her endurance is gone, broken down by the endless flogging. Tears leaking from her eyes, she allows you to flip her around, tying her hands to the middle of the post and her elbows higher up, forcing her to bend backwards and thrust her breasts forwards. Her limbs are trembling with exertion, and her eyes are bloodshot and dry. Her mouth hangs open as she desperately sucks in air, making her chest heave, and she watches you, dreading the pain you are about to inflict upon her, but still refusing to resist or struggle or even complain really.

Despite yourself, you are impressed by her fortitude, and decide to make this relatively quick...and perhaps even let her off for now. After all, considering what you have planned, it's not like that is going to spare her much pain. So you pick up the thinnest cane, seeing a few flicker of relief in her eyes, and give her a rapid dozen, striking as fast and hard as you can, leaving pink weals. Imogen yelps and howls, starting almost before you first hit her and not ending for several seconds after you stop.

When you finish, her mouth is hanging open, your cock is rock hard, and she can still barely stand. She still manages to muster enough strength to ask you "How would you like me now Sir?"