Move the sliders! Stamp: All Gobos will stamp themselves. Number of Gobo Bros: Slide to adjust the number of Gobo Bros there are on stage. Speed: Change the speed of the Gobo Bros Angle: The Gobo bros will keep turning in the angle you put. Clear: The screen will clear when Clear = 1. Pen Size: Changes the size of the pens. Change pen colour by: Changes the colour of pens.