What's the difference between bookcases with glides versus those with flat bases?

Bookcases with adjustable leveling glides (small threaded feet at each corner) are far easier to level on uneven floors — just turn each foot until the unit sits perfectly plumb. Flat-base bookcases look cleaner from the front but can rock or gap at the floor if the surface isn't perfectly level. In commercial buildings with concrete subfloors or older flooring, leveling glides are a practical necessity. They also allow a small air gap at the floor that can help prevent moisture issues. FindOfficeFurniture.com carries commercial bookcases with leveling glides — call 888-719-4960 for the best deals.