Crop the design
Drag the box to cover only the tattoo itself, with no empty margin around it. The crop becomes the actual size of the design, so any blank paper or skin left inside it would make the preview scale wrong.
Prototype — light version. Pick a placement, upload a reference, position it, and download the image to show your artist.
You'll be asked to crop tightly around the design next — that also lets us key out the white/paper background automatically, so only the ink shows on the skin.
Drag the box to cover only the tattoo itself, with no empty margin around it. The crop becomes the actual size of the design, so any blank paper or skin left inside it would make the preview scale wrong.