Colours normally range from yellowish-brown to very dark brown.
Other colours and combinations of colours frequently result from variations in maturity or cultural and curing techniques. When presented in the piece, bolting cloth, not made up, must be indelibly marked in a way, which undoubtedly identifies the goods as being intended for bolting or similar industrial purposes. The thickness of the lines forming the sides of the rectangle is 5 mm, and that of the diagonals 7 mm. The rectangle measured from the outer edge of the lines is at least 8 cm in the length and 5 cm in width. Customs authorities may accept other markings where these markings undoubtedly identify the goods as being intended for industrial purposes like bolting, filtering, etc.