Today I stumbled across an interesting feature of flash and CSS3 that I thought might be interesting to someone.

If you have ever done much work embedding flash onto a website you will have come across the wmode parameter. If you set wmode=”transparent” then the swf file you include will behave properly and obey your stacking (z-index) commands.

Today I discovered that this parameter also allows you to apply CSS3 border-radius to a container of a flash movie – if your swf takes the same amount of space as its container, then if you apply a border radius to the container if will also crop the swf.

I couldn’t find that documented anywhere, so I hope it helps someone.