Example of selection of corks in a fibril at t = 750 s. The Hα line intensity proxy is shown in panels a and b. Panels c and d: density in the xz-plane along the magenta line in panel b. The locations of all corks in a fibril are indicated in green, while the fibrilar corks located along the xz-cut are indicated in magenta in panel c. The white curve shows a magnetic field line passing through the fibril; fibrilar corks located on or very close to the field line are shown in blue.