FIG. 1 is a perspective view of a first embodiment of a chair back showing my new design.
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a side view thereof;
FIG. 5 is an opposite side view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof;
FIG. 8 is a perspective view of a second embodiment thereof;
FIG. 9 is a front view of FIG. 8;
FIG. 10 is a rear view of FIG. 8;
FIG. 11 is a side view of FIG. 8;
FIG. 12 is an opposite side view of FIG. 8;
FIG. 13 is a top view of FIG. 8;
FIG. 14 is a bottom view of FIG. 8;
FIG. 15 is a perspective view of a third embodiment thereof;
FIG. 16 is a front view of FIG. 15;
FIG. 17 is a rear view of FIG. 15;
FIG. 18 is a side view of FIG. 15;
FIG. 19 is an opposite side view of FIG. 15;
FIG. 20 is a top view of FIG. 15;
FIG. 21 is a bottom view of FIG. 15;
FIG. 22 is a perspective view of a fourth embodiment thereof;
FIG. 23 is a front view of FIG. 22;
FIG. 24 is a rear view of FIG. 22;
FIG. 25 is a side view of FIG. 22;
FIG. 26 is an opposite side view of FIG. 22;
FIG. 27 is a top view of FIG. 22; and,
FIG. 28 is a bottom view of FIG. 22.
The broken line showings of the star shape in the drawings illustrate portions of the chair back that form no part of the claimed design. The broken line showing of the chair seat, base and arms illustrates the environment of the claimed design and forms no part thereof.