What type of sanding material should be use to sand the white ceiling after patch?

[compiler]

My white ceiling has a crack. I tape and patch it.Then I begin to sand it for paint by using the sanding sponges. But, it causes dirt, black stripes in the sanded area. Has I used the wrong sanding material to sand the white ceiling? Thank you for your answer.

[HayZee518]

your choice of sanding types is really your choice. sanding sponges are ok as long as they don't fall apart. I'd use an open weave sanding pad of the 120 grit. regular silicon-dioxide paper would be my next choice