Universal and special indicator papers are supplied in plastic reels that ensure long term stability and protection against many external influences. The indicator paper will always be ready-to-use when needed. For each pH-value these papers show a single colour which can be matched with the colour scale. For many applications. - Roll of 5 m. - 7 mm width. Universal and special indicator papers are supplied in plastic reels that ensure long term stability and protection against many external influences. The indicator paper will always be ready-to-use when needed. For each pH-value these papers show a single colour which can be matched with the colour scale. For many applications. - Roll of 5 m. - 7 mm width.