The reverse side of the reflex reflector shall be brushed with a hard nylon brush and then covered or thoroughly wetted with a mixture of petrol and benzol (proportion 90 : 10) for one minute. The mixture shall then be removed and the reflex reflector allowed to dry.
As soon as evaporation is completed, an abrasion test shall be carried out by brushing the reverse side with the same nylon brush as before.
The CIL shall then be measured (V.3.2) after the whole surface of the mirror-backed reverse side has been covered with indian ink.
