There is some debate over which materials are acceptable for use as a green screen. Many professionals will tell you that the colour must be just the right shade of green, or that the screen must be made of certain material. It is certainly true that some materials and colours are better, but in reality you can make an effective green screen from just about any smooth, green surface.
If you really want the best possible screen you should do an Internet search for green screen material. There are numerous websites which sell specialist material and with a little research you can find something to suit your studio. Be aware that professional green screen material can be quite expensive.
In the more likely event that you would like a cheap option to get started with, you will be glad to hear that it’s not hard finding useable material. There are three main options:
Use a solid material such as cardboard or wood, painted green.
Use flexible or spongy material such as foam, spandex, etc. If you’re going this way, you are probably better off to buy professional material.
Use some sort of fabric. You can either buy green material or buy white material and paint/dye it green.
Go to a good fabric store and look through the selection — you should be able to find at least several choices.
The material should not be too reflective — this tends to create lighter “hotspots”.
Lighter, brighter green is better than dark green.
Material which is crease-resistant is very desirable. Wrinkles are the enemy and you will appreciate material which can be set up and moved without destroying the smoothness.
Heavy material is good for providing consistent colour, especially if there is any possibility of anything behind the screen showing through. However it can be prone to more creasing.
If you need to pack up the material for storage or moving, roll it rather than fold it — this helps reduce wrinkling. It’s a good idea to use a cylindrical object with a diameter of at least 5-10cm (2-4″) to roll the material onto, for example, the heavy cardboard cylinders used as the centre of newsprint rolls.
You may want to iron your material from time to time to keep wrinkles away. If you are going to paint or dye the material, make sure you will be able to iron it. Note than ironing a piece of material this large without creating new creases can be a challenge.
Hang the material in whatever manner suits your situation. For example, you could use thumbtacks or a shower rail attached to the wall. To make a mobile screen, use two stands (such as light stands or mic stands) and mount a rail between them. You could also make stands from clothing racks, hat stands, or any similar type of frame.
Cardboard or wood has the advantage of providing a nice consistent surface, free of wrinkles. The disadvantage is that it’s more difficult to pack up and move.
Although you can use any light, bright green paint, it is better to use a tint designed for green screens. Do a search for “chroma key paint” to see some options.