Pixelated Background After 3D Render

[stef.salmon]

Hi,

I'm newbie to Sweet Home 3D.
I'm trying to produce a simple 3D floor layout by tracing over an imported png. It's quite a simple thing I'm trying to do.

When I do the 3D render I get some slight pixelation on the background.

Any ideas as to why this happens?

Many thanks.

[Puybaret]

Maybe choose a better quality or/and more pixels.