I used 4mm MDF for this design as it gives a nice contrast of colours for the dog picture when engaged. 

If you plan on using this sign outside you could engrave this design on a different wood or acrylic instead.

The red layer in this file is the cut line.

These are the settings I usually use for engraving MDF using the xTool D1 Pro 5w as they give a good result while being relatively fast.