Controlled Variables

Controlled variables in my experiment were as follows:
.time each shape of material held on to the weight (10s)
.the size of each shape of material (25 square centimetres)
.where the material was held (by the edges)
.the quality of the material before experiment (no rips
.the plastic bag used to hold each weight (same bag with weight of 6g).
.the dimensions for each shape were kept the same (12.5cm X 2cm rectange)
.the impact of the sudden weight on them (gently lifted from carpet after starting
stopwatch)