For these I used the insert from an Ikea shelving unit. It is 3 sided, 12" flat black. Give it a little angle so there is no shine from the sun. It is mobile and easy to arrange in the back. Also, if the flower is in a pot, I use stairs to position them. I tried using GIMP to edit photos, but it is way too hard with no one around to explain how to do things, so I have to get inventive.