The good news is YES!! you can paint Matt emulsion over the following surfaces

Silk
Eggshell
Mid Sheen
Satin
Soft Sheen
Gloss Paint

However as with all good decorating projects the secret is in the Prep!!! If the walls are not prepared properly this can lead to the appearance of fine hairline cracks all over the walls

To begin with you need to provide a key for the new paint to stick too.

You do this by sanding the areas you want to paint with 80 or 120 grade sandpaper.

Ideally you need to remove any sheen or shine from the wall surface. The best way to do this is with the use of an electric sander. Bear in mind this can be a dusty process so it would be advisable to wear protective clothing and a dust mask. You may also want to tape up any doors and open windows to help the dust escape.

Another option would be to seek out local a local Painter and Decorator who uses a Dustless Sanding System. When you call just ask the Decorator if they use a Mirka sander for their prep work.

This would reduce the dust in your home dramatically. Once all the sanding has been completed, it is good practice to wipe down the walls with a damp cloth to remove any dust or contaminates that could effect the paint sticking to the wall.

Now you have completed the dusty business of sanding, you now need to prime the wall area. We have found the best product for this is Zinsser Gardz avaiable from most good Decorators Merchants.

A 5 litre tin costs about £40.00 and covers around 50m2 of wall.

To calculate how much Gardz you need use this Paint Calculator

Allow the Zinseer Gardz to fully dry and now you can apply the matt emulsion without any problems.