We use plastic pots. Most of our seedlings are in 2.25-inch rose pots, and those that are a little more mature are in 3.5-inch pots. For larger plants, the pot size must be appropriate for the plant. In choosing the correct size for the new pot, it should be large enough to accommodate at least two years of new growth. We have used clay pots, and certainly they will work. However, for paphs especially, we highly recommend our coconut husk mix in conjunction with plastic pots. The plastic pots help retain more even moisture in the mix and slower overall drying out at the roots.