When can I wrap him on my back?

[movingsouth]

I have a wrap -- OK ok, its an old twin sheet made into one...cheap! it was my first baby's wrap for a very light not-on-the-charts baby. Now I have a Buddha belly child and might upgrade to a real wrap in interlock for him.

But I digress.

When can I wrap him on my back rather than front? (he's 2 months and has decent neck strength, was never a floppy headed baby.) It seems if I can wrap him on my back and provide head support then he can wrap anytime but if I wrap without head support then i need to wait for him to have solid neck control?

any wrapping ladies with thoughts/experience? this buddha belly boy is breaking my back!