A plastic dust sheet is not automatically ready for another job because it can still be folded. Reuse depends on the product's guidance, the condition of the material and what the next task involves.
Inspect before folding it away
Look across the whole sheet for tears, stretched areas and contamination. Pay particular attention to edges and points that have been secured or pulled around corners. Check both sides, not only the face you can see while it is on the furniture.
A sheet that looks clean from a distance may still carry marks that could transfer to another surface. Keep a damaged or uncertain cover away from the ones you intend to use again.
Do not turn cleaning into a new problem
Follow the product guidance for cleaning, if any. Do not assume that a solvent, abrasive pad or hot wash is compatible with the plastic. If the material cannot be made suitable using the stated method, choose a replacement for the next job.
Do not store a cover with wet residue or an unknown substance folded inside it. Follow the paint or material manufacturer's handling and disposal advice for contamination.
Store with an identity
For a suitable clean cover, fold it without excessive force and put it somewhere protected from sharp objects. Keep the original pack label, or add a note recording the product and any limits you need to remember.
Separate unused sheets from previously used ones. The next person opening the cupboard should be able to tell the difference without unfolding every cover.
Check again before reuse. Storage does not repair a tear or establish suitability for a harder job. Treat each new task as a fresh decision about the sheet's condition and intended use.