Some PLA and ABS plastics I have used are VERY sensitive to needing a layer cooling fan. Many 3-D printers do not have them, but they can be added fairly easily, and will improve your prints in most cases even if you don’t NEED it.
Most recently we purchased some lubricated PLA from Filament Express that required it. We liked the color and smoothness of the prints but it needed a layer cooler. Our SeeMeCNC printer at work came with a layer cooling fan, but my Makerbot did not. I added one and it improved all my prints. This filament needed more then just my basic layer cooler, I had to add a much beefier fan AND a 120mm PC case fan to get good prints with it though. So if you are getting print quality issues, shrinking layers, messy upper ones, or poor bridging, look at improving your active cooling.
Left: Layer cooler/active cooler fan added to Makerbot replicator
Right:Before fan added to Makerbot.