weight/gauge of paper (we use GSM as the unit, in Australia);
eg. photocopy paper = 80gsm, newspaper =~45gsm, pad paper =~65gsm,
A4 cover paper = 125gsm, large card (at St Al's) = 220gsm
size of paper (therefore, mass of plane)
length of body of plane
width of wings of plane
depth of body of plane
style of plane (way it is constructed) - such things as wing and tail flaps, nose weights etc are also part of this
throwing style (not really one that we would want to test, I wouldn't think, but needs to be considered)
wind (environmental factors)
height of starting point
method of measurement of distance (perpendicular to throwing line/in a straight line to where plane hit the ground...)