The pattern bounces on the edge of the stage. Go to Settings, choose “Stage size ...” and define the size of your “stage”. The values are given in pixels where 50 pixels = 1cm. So, if you want to design a pattern with a maximum size of 15cm x 15cm, choose the values for “Stage width” and “Stage height” each 750. Calculation in inch: 127 pixels = 1 inchDesign a pattern with max. size of 6inch x 6inch = 762 pixels for "Stage width" and "Stage height"