Specifications adopted by the Cotton Duck Association specify that duck shall be made of cotton, free from waste and thoroughly cleaned, evenly woven, free from all sizing and free from an excessive number of avoidable imperfections in manufacture. Duck is numbered as follows: No. 1 duck is 22 in. wide and weighs 18 oz. per linear yard and is taken as the basis. For each ounce under 18 the number is increased by one which would make a 17 oz. duck 16 oz. /t3 and so on up to #I2 which weighs 7 ounces. Duck heavier than 18 oz. per yard is numbered by ciphers, a cipher being added for each ounce increase in weight.
i Thus i/o =19 oz. duck ; 2/0 = 20 oz. duck. Duck is made as heavy as 20/o which would weigh 38 oz. per yard. However, duck above 2/0 is very seldom used.
The numbering of duck conforms in England and the United States in number only. English specifications are based on a 24 in. fabric and on two ply yarn warp and filling for all numbers, while in the United States 22 in. is the standard width and designates that each number shall be more than two ply and varies with the number and the weight per running yard for specified widths in exact proportion. Thus a 24 in. duck would weigh more than the standard 22 in. goods, while I 1 in. duck would weigh one-half as much as the standard width. Duck is made
in widths from 14 to 120 in., but the most common widths are 22, 28 and 36 in., and are delivered in standard lengths of 110 to 120 yd. differing from the English requirements of 4o yd. lengths. Duck in the United States is known as hard, medium or soft texture. Hard duck is made from 2/o—p2, and medium texture 2/o-16.
The English specifications for a ttu duck specifies it should weigh 18.8 oz. per yard, 24 in. wide, be delivered in a 39 yd. bolt, to weigh 46 lb. containing 26 lb. of warp, 66o double ends (approximately 28 ends per inch) and 20 lb. of filling, breaking 340 lb. in the warp and 48o lb. in the filling, using the Avery method of breaking a 24 X I in. test strip. Comparing this with the U.S. Government specification a #i duck should weigh 18 oz. per linear yard, 22 in. wide, have as a minimum 26 ends and 19 picks per inch of 5 ply warp and filling, and specified widths should weigh in proportion to the 22 in. standard (that is, a p duck 24 in. wide should weigh 19.6 oz. per yard). The fabric when tested by the I X I X3 in. grab method, should break 44o lb. in the warp and 37o lb. in the filling. The difference in breaking strength is partially due to the method employed, therefore no comparison can be made. (R. T. F.)