Those on a plain saddle consist of a bag made of leather and serge, stuffed with flock and horsehair, but in military saddles they have been long discarded.  In face of the fact, however, that all types saddle are used in war, including those with hair panels, it is necessary the subject should receive some consideration at our hands.

Stuffed panels
Panels stuffed with hair have one very great advantage,viz., that in course of time they get moulded to the shape of the horses back, and adjust themselves to all irregularities.  This is the explanation why so little attention is paid to the fit of the plain saddle; so long as the front arch is wide enough, the saddler does not trouble his head any further, but depends upon the hair in the panels completing the fit, which it most certainly does.  This adjustment of panels to the shape of the back is very noticeable; the stuffing in a new pair of panels will with very little work settle down, so that the panel becomes reduced in thickness; and while the settling down is taking place the two bags of hair are being moulded to the peculiarities of the back, and the saddle made to fit through its panels instead of through its tree.

Theoretically this is wrong in principle, though it certainly works out in practice, and may, therefore, be defended; but for the panel, the civil saddle would be a constant cause of a sore back.

Weak points of panels
Panels have their weak points, they may be too bulky or too thin, the stuffing may have become hard, lumpy, or even caked if sweat has passed in.  Until every soldier knows something of saddlery, it is fair to urge that the panel requires a saddler to deal with it, whereas there are other means much simpler, such as a blanket, which a soldier may adjust for himself.  No doubt it is owing to this the panels have disappeared from the regular service of the Army, as their alterations can only be affected by a trained man.