Try storing your slides in the fridge at –20 °C. It may take at least 3 days to dry completely at this temperature. According to my experience, this is the fastest and the most convenient way to dry and harden your slides.

Hi Salma Abdelmaboud

Use a single drop of mounting medium. Coat the outside of the coverslips with white nail paint and keep it in room temp for 5 mins. That should be sufficient to dry the slides. I store the slides in 4 degree refrigerator.

* You may be facing the issue due to over pouring of mounting medium.

Thanks

Samir