The foundation of all 3d prints is a good first layer. First layer performance becomes even more important when printing thin structures like the wings on the high performance flying gliders available here at threedsy.com.

Above, typical results when the nozzle is too far from the print bed. Notice the un-fused lines, sieve like appearance, and the way that the print improves on the upper layers, indicating the problem as a first layer issue. The lines are from oozing during travel, as these pieces were printed without retraction to better illustrate the differences.