White cupcake cases

I am experimenting at the moment looking for the perfect white cupcake cases for a wedding in July.

I am after cases which are thick enough to stay white whilst cooking without showing too much mixture though - this sounds easy but i am struggling to find any...

This is an experiment with Dr. Oetker muffin cases bought from Tesco. As you can see a lot of the mixture shows through the cases. I am not happy with them at all for this purpose.

The search continues...