Old, Old Silk Line Designations

I occasionally get questions on old line designations, so in this post I want to discuss the old, old system of line sizing. Originally, silk lines were not designed by the weight standards that are in play today. Rather they were designated by a simple numbering system, 1, 2, 3, etc. Later the numbering system was converted to an alpha system in which the line diameter was designated with a letter, for example HDH (a double taper of about 6 weight).

Kingfisher was a producer of lines for many years, and one can find  their silk lines yet today. The Phoenix line  (Silk Lines), currently manufactured today, is built on the Kingfisher tradition. The new lines are all categorized by weight, like all other modern lines. But in the original system a Kingfisher line number 1 is the same as an AFTMA 3 and the Kingfisher 7 is the same as an AFTMA 12. The AFTMA scale, as you know, is sliding, but we don’t know what the Kingfisher scale was. However, if we assume that the Kingfisher lines 1 through 7 were evenly spaced in terms of weight (most likely the case), then their number 1 would be 100 grains and their number 7 would be 380 grains. Therefore each line would be 46.67 grains heavier than the previous line (380-100/6 = 46.67). So, the lines would go like this:

Kingfisher #/wt    AFTMA Equivalent
1–100 g.                       3–100g +/-6g
2–146.67g                    5–140g +/-6g
3–193.34g                    7–185g +/-8g
4–240.01g                   9–240g +/-10g
5–286.68g                  10–280g +/-10g
6–333.35g                   11–330g +/-12g
7–380.02g                  12–380g +/-12g