Bromide drag lines are a byproduct of development with no agitation. High concentrations of bromide is produced around the perforations and overexposed areas. Without agitation it slowly slides down the surface of the film, inhibiting development and creating drag lines. Surge marks look similar but are cause from the opposite, over-aggressive agitation. Surge marks will appear as lines going the same direction as your agitation. Bromide drag will appear as vertical lines because they are caused by gravity.
Need more help? Click "submit a request" below.