There are a few posts about this type of heading, and I believe a few of the high street readymade suppliers sell curtains like this, I know IKEA do.

[attachment=0:13vegdrv]hidden tab top.jpg[/attachment:13vegdrv]

You can also buy tape here http://www.curtaingenius.co.uk/shop/....asp?prod=1788 that gives the same effect.

Here is a site with instructions on how to make them from scratch http://www.isew.co.uk/sewing_techniq...ps-c-00675.htm They are pretty simple to make and do not involve any special materials or techniques if you make the tabs from fabric.