If you'll want to crop your design, do that before erasing parts. Cropping is also accessible from the Customize & Resize step where you enter your design's full size in the Customize Tab.
Use the Designer: (requires the Designer or Pro version of Rapid Resizer)
- From Customize & Resize step where you enter your design's full size, click Customize then Designer .
- In the Designer, click on the Image Eraser tool.
- The Line width setting lower down controls how large the eraser is.
- Click and drag within an image to erase parts.
- When you're done, click the Print button.
If you're trying to erase lines and shapes drawn in the Designer, select them using the Select & Move tool then click the Delete button or backspace on your keyboard.
If you would like to remove a white background, you can use the Clear White option.