The best way to keep cucumbers crisp is to wrap the whole cucumber in some paper towels.
Then place the cucumbers wrapped in paper towels in either a plastic container or in a plastic bag and then refrigerate the cucumbers.
Doing this will keep the cucumbers crisp until you're ready to eat them.
If the cucumbers are sliced you can place the sliced cucumbers into a sealed container.
Stack the cucumber slices in the sealed container and then place a paper towel over the top of the cucumbers.
After that is done then cover the container with the lid and place the container of cucumbers into the refrigerator.
The sealed container and paper towels will help keep the cucumbers crisp while in the refrigerator.
The cucumbers in the refrigerator in the sealed container should last for up to a week.