Cork defects percent - Tangential section protocol

Defects are quantified in the two tangential of 20 × 20 cm boards cut from the previous 30 × 30 cm boiled planks, and also in four strips of 20 × 1 cm (obtained from the same 30 × 30 cm samples), corresponding to Tangential surfaces (two strips for each surface). Each of the four faces of the 20 × 20 cm boards and the two faces of the 20 × 1 cm strips were photographed with a camera (10 mega pixels resolution). The defect areas were measured by image analysis, defining the limiting color threshold by visual inspection, using the Leica QWin software (V3.X—Leica Microsystems, Germany). Lengths were calibrated using a calibration ruler. The two types of defects (cork porosity and nail inclusions) were measured separately and the defect areas were expressed as a percentage of the total area of cork under analysis.