What width should my background images be for tumblr and twitter?

[Shayna]

I make them 1024px wide and upload them but the come up about 400 pixels short and just get filled in with a back ground color on the right hand side. If I make my images longer and longer, this does fix the problem. But it confuses me. I thought 1024 was standard. Why is this happening? How many pixels are they looking for exactly? Thanks for any help you can give me.

[Your Shadow]

Choosing Dimensions for Your Web Page Layout:

In Search of the Holy Grail: http://www.alistapart.com/articles/holygrail/
Choosing Dimensions for Your Web Page Layout: http://www.elated.com/articles/choosing-...ge-layout/
How to create flexible sites quickly using standards like CSS and XHTML: http://www.ibm.com/developerworks/web/library/wa-rapid/
Care With Font Size: http://www.w3.org/QA/Tips/font-size
Designing for the Web: Resolution and Size: http://sitepointcom.createsend4.com/t/y/...irtthtw/h/

Ron