That's when I hit on using this idea:
All of my Italian Wars flags are wrapped around narrow gauge aluminium or brass tubing (from model shops) with a spear point casting glued into the top to finish it off. These slot over the banner bearer's 'flag pole'. The tubing is not very expensive, and the cost benefit analysis is obvious. If I want to field a new combatant all I have to do is make a new flag - the figure having been painted ages ago.
To prevent damage to flags that are not in use I store spare flags as shown below.