filter disc having a maximum pore diameter in the range of 10 to 15 microns supported the weighed sample within the funnel the funnel was filled with blandol white mineral oil having a specific gravity in the range of 0 845 to 0 860 and 60 u00b0 f from whitco chemical sonneborn division and the sample was weighed and placed under 0 5 psi pressure on the filter after one hour during which the miniscus was maintained constant at a given height starting at 35 to 45 centimeters the sample was removed weighed and the grams per gram absorbed calculated the height was adjusted and the process repeated with a new sample until a height of one centimeter was reached results were plotted in fig3 in general the results obtained below 20 centimeters oil indicate oil contained within web voids and results obtained above 20 centimeters oil are significant as representing oil absorbed within the fibers themselves which is a factor in wiper retention bulk was determined using an ames bulk tester model 3223 equipped with a long range indicator having 0 100 units with 0 001 inch graduation over a full span of 3 inches a j50b wisconsin bearing company universal joint was attached to the bottom of the vertical weight attachment rod and to the top of a 5 inches by 5 inches platen with total weight of 0 4 lb u00b1 0 01 lb ten 4 inches by 4 inches samples without folds or creases were stacked with the machine direction oriented in the same direction the platen was centered over the stack and released gently after 15 to 20 seconds bulk was.