Paper flowers are designed to be strong and particularly durable. They can be stored for years without degradation. Some of my flowers are still intact today.
Most of the time these flowers will certainly be used in your home, probably on a piece of furniture in the living room. In this case experience has shown that it is necessary to apply a few small rules to ensure longevity to the flowers.
It is important to find a system so that the flower remains rigorously in a vertical position. Indeed, if it is bent, it will twist with time under the effect of its own weight. Personally I pour rice in a glass or a small container with the flower in the middle while keeping it upright. This system works very well.
You could of course put something else than rice since it is granular and that it effectively maintains the flower without causing it harm. Indeed some materials can react with paper in the medium or long term.
It is sometimes tempting to put several flowers in the same container but I do not recommend that since the container is not wide enough to ensure spacing.
The first reason is that I think the flower is best promoted alone in its container. In addition, if the container is not large enough, there will necessarily be friction between them, so there is a risk of deterioration with time. Finally, in a small container, they will not all be able to stay straight.
The idea is to avoid them getting bothered that's why I recommend to put them each separately in a container with a vertical position.
This is a common sense rule. The flowers being made of wadding towel or microwafeled for the most part, it is obviously necessary to put them in a space so as to avoid any contact with liquid. Do not place it in a wet area like the bathroom. I do not recommend kitchen or cooking areas, there is steam during cooking and smells can cling to it. Do not put it outside, it will be subject to wind, insects, rain and moisture.
-Do not put your flower in a bottle, it's the best way to twist the flower with time
-Do not carry your flower in a bag or other. Always put it in its transport box otherwise keep it in your hand until you put it in a safe place.
-Avoid to manipulate it too much, it's made to be watched ;-)
Finally, if you do not use it for a specific purpose, keep it in its box. This is the safest way to preserve it sustainably.