Acrylic paintings are extremely durable and long-lasting but to maximise their longevity there are a few tips you should be aware of.
Don’t leave the painted side in contact with other surfaces
Because acrylics are a type of plastic they can undergo change much more easily that harder substances. If you leave your painting in contact with other surfaces during changes in temperature (e.g. the heating in your home coming on and off) the two surfaces can stick together. This process (known as ferrotyping) can cause damage to your painting.
The top varnish layer would almost always prevent any permanent damage to your painting but it's best to avoid this by not leaving the painted side in contact with other surfaces.
Avoid extreme temperatures, especially cold ones
Acrylics can crack if they get too cold. While this is more likely to occur during the curing process (the time it takes for the paint to go from being touch dry to complete water evaporation) acrylic paint manufacturers generally recommend that you avoid keeping acrylic paintings in any environment close to freezing and below. In practice, professional quality acrylic paints are very resilient and the painting will have fully cured prior to being varnished but it's still best to avoid extremely cold temperatures — especially for long periods of time.
Keep it out of direct sunlight
Even the highest quality pigments combined with a UV protection-containing varnish will fade if exposed to too much UV light so hanging your painting in direct sunlight should be avoided. If you follow this tip your painting will last for many many decades, possibly centuries, before there is any noticeable change in colour.
Remove dust correctly
A good varnish will form a harder surface than acrylic paint making it more difficult for dirt to embed itself. However, to avoid damaging the varnish layer dust shouldn't be removed with cleaning products or abrasive scrubbing. Simply wipe the painting down with a dry cloth or brush down with a soft brush.
Don’t drop it!
A painting on a wooden panel is probably at it weakest on the corners. If you drop a painting painted on MDF or hardboard and it lands on a corner it could cause serious damage to the painting. Likewise, canvas can tear if dropped on a sharp object. Handle with care!
This is really awesome! Would totally frame it and put it on my wall. Good job!