one side to the other. The beads, and excess toner, are captured on the lower edge of the device to be reused. This process can be repeated several times in order to develop all areas of the document. Aerosol spray method: Some EDDs provide the ability to spray toner over the surface of the charging film. In these systems a protective shell or chamber is fitted that covers the entire platen. At one end there is a nozzle connected to a reservoir of toner. The examiner then manually activates a pump that sprays toner into the chamber creating a cloud of fine toner that settles down onto the surface of the charging film. Ideally the cloud is randomly distributed but often this method produces a relatively distinctive pattern of toner on the film. Brush method: With some EDDs the toner is applied using a magnetic brush such as would be used for development of latent fingerprints. This is a manual process that is quite tedious and requires meticulous control of the brush. But the method works well for selective development of subtle indentations. Toner pad method: Similar to the brush method described above but uses a special pad with a built-in toner reservoir. The toner pad is placed on the surface of the charging film and moved across the surface by hand. Assessment of results. After the development process is complete the examiner must assess the results of the test process. FFU test results: since the questioned document may or may not have indentations, the correct method to assess the functionality of the EDD is through inspection of the FFU test sample. If indentations are developed from the FFU test sample, the EDD can be considered as functioning correctly. If no indentations developed from the FFU test sample, the EDD is not working. If the FFU test was positive and no indentations are developed in the area of the questioned document, then the assessment will be that no detectable indentations have been developed. It is important to note that this does not mean the questioned document was never in contact with other items of interest. The absence of detectable indentations may be due to one or more limitations causing the indentations to not be detected. Note that the presence of indentations in the document area is prima facie evidence that detectable indentations exist such that the FFU test is redundant.