The phrase "affixed to the back" is correct and usable in written English.
It can be used when describing something that is attached or secured to the rear side of an object.
Example: "The label was affixed to the back of the package for easy identification."
Alternatives: "attached to the rear" or "secured to the back."
fuel — affixed to the back.
Affixed to the back of the stage was a five-foot-tall photograph of the moon.
Affixed to the back steps is a hand-lettered sign that reads, "Trespassers are subject to eternal biblical curses".
With invitation to Margaret, Alfred, and Violet Hunt to visit the Holman Hunts at their home on March 6 [n.y.] affixed to the back.
Simple 3V LEDs were affixed to the back of each bin to be used as indicator lights for which bins should be opened.
One man arrived from Brooklyn, riding north with a wagon of cider and Newtown Pippins affixed to the back of his bicycle.
Often, this surfaced in notes affixed to the backs of the photographs.
Canvas paintings of reclining nudes by Katherine Blackburne affixed to the backs of sofas serve as art.
At tradition-rich Keeneland last month, Hansen surrounded himself with female employees with blue tails affixed to the backs of their form-fitting white dresses with patches that screamed Hansen in glitter.
They are affixed to the backs of the camels, and camel owners and trainers with remote controls would race in their luxury cars alongside the robot riders on the track.
Other such new media ventures include trucks that drive through city streets, displaying billboards; ads beamed on the sides of buildings; racks filled with postcard ads, which are placed in restaurants, bars and nightspots; ads printed on coffee cups and posted on coffee carts, and even small signs affixed to the backs of messengers' bicycles.
