Indicator device for detecting the amount of sebum in hair and scalp and method therefor

An indicator device for contact with human hair or scalp for determining the oiliness thereof, comprising (a) an oil-absorbent sheet material capable of absorbing sebum from the hair and scalp, said oil-absorbing sheet material being dyed on a surface with (b) an oil-soluble dye, soluble in sebum, capable of giving a visual physical color change in the area when placed in contact with sebum to form a spot of differing color when the dye dissolves the sebum of a size proportional to the amount of sebum absorbed by the oil-absorbing material, and (c) a non-adhering oil-permeable transparent sheet material permeable to said sebum adjacent to and superimposed over said dyed surface, said oil-permeable sheet forming part of an envelope enclosing said dyed oil-absorbent sheet, and allowing passage of sebum when brought into contact with sebum, whereby said sebum is absorbed by said absorbent sheet material to effect said visual physical color change which is visible through said transparent envelope surface.