You can store any non-stimulus files in the myfiles subfolder, located within your main experiment directory.
Contents of this folder are preserved when the experiment is deployed and are automatically included in the .ebz package file. Unlike other subfolders, the myfiles folder is safe from overwriting during test runs in Experiment Builder.
Contents of this folder are preserved when the experiment is deployed and are automatically included in the .ebz package file. Unlike other subfolders, the myfiles folder is safe from overwriting during test runs in Experiment Builder.

