Dyeing Fabric in a Front Load Washer

I have a front loading washing machine. I used to dye things in a top loading one. The material in question is too large for a pot. How do you use the dye in a front loading machine? The water does not come in till all the material is in it and it is weighed and then the water comes into it.

The amount of water added depends on how much weight is in it. I cannot think of a way of doing the valances. Does anyone know how to make it work without it becoming blotchy?

By jutta