Weed Spraying Warning sign with stand combination. Choose from 450mm wide or 600mm x 600mm signs. In general, this Weed spraying in progress sign and stand combo, is used around schools, facilities and Body corporate properties. Indeed, anywhere where wind will drift spray, or where there is a danger to others. Stands must be placed at all area entry points. Choose your sign size. Image and stand will differ depending on size selected.