Greenhouse flooring material that retains humidity

[Chloe]

Hi, this is my first post and I have a problem with low humidity in my 10x12greenhouse. The present floor is smooth concrete. The type of material that I would need on my floor to retain humidity must also be non-skid and also look great (since it is seen from my family great room and kitchen area). I've contemplated small pea gravel, but it would be slippery and also look messy from spilled bark,etc. Any ideas would be much appreciated!!