Thank you all for your ideas!
I've decided to make the quilt one and a half times wider than the opening; I'll use a very thin batting and an extra wide cream backing that I've seen online which has a tone on tone print so it is a little bit more interesting than a plain but shouldn't fade in the sun; DH and i have been looking at curtain tracks and have found a rail with a groove on the underside with rings that run along, then some hefty metal hooks in wide curtain tape on the back of the quilt - this should hold the weight, no problem; whether I gather the tape or not, we'll see when it's done, try it ungathered first as izy suggested! as they say in france 'au fur et à mésure'! :wink:
I'll definitely make a tie back and if I've got enough fabric, i like the idea of a valance. This would work even though i plan to hang the curtain outside the recess as there is a cross beam in the ceiling a couple of inches in front of where the curtain will hang!
i also just love the idea of a mini quilt for the catflap, (butterflywing! :D ) and even though i won't make the quilt fitted to the door because i want to pull it right back in daytime, I might make a mini curtain for Barney's door just for fun!
It may take a while as I'm currently researching a new sewing machine (hooray!) so will wait til I get it to start on the curtain. I've already designed a pattern though (ohio stars alternate with three strip blocks in three colours - dark red, navy and old gold) and yes, I've already bought the fabrics! :wink:
Will keep you posted, thanks again for all your help!
K x