Yes, you're right. Shades, valances and cornices should have a split piece on either side for aesthetics (can't say I ever heard of a weak center seam tho) and drapery panels are seamed down the middle when 2 full widths are joined. Perfectly acceptable and an industry standard, and why give yourself more work :)

Thanks for responding. That's what I was hoping to hear. Now I'm trying to figure out how to do the lining. I know to make the fabric piece wider than the lining piece, so the fabric wraps around the sides a bit; I did that with my roman shades. I'm thinking just a regular 1/2 inch seam at the top, but I don't know how to do the hem. I realize that the lining should be shorter than the finished length to avoid a lot of bulk in the hem, but I'm not sure how to go about it. Any suggestions or online sources of directions you can steer me to would be appreciated. Thanks again.

I don't pillowcase my panels, but instead do a double turned hem, heading and side hems and either hand sew or use a blindhemmer. There's pretty good directions in the Singer "More Sewing for the Home" book. If you prefer to pillowcase, there's directions in the link below.

Here is a link that might be useful: Lined curtains pillowcased

Thanks so much. You have been so helpful. I think I'll just "pillowcase" them, since I've done it before and the link you provided makes it very clear how to do the hem. I really appreciate your guidance.

You're welcome, Valleykat! The important thing is to have fun!

Here's something else to think about..Make sure to use an even number of grommets, otherwise both ends will not be towards the wall. Also, if the grommets are big, the lining fabric will be visible from the face, so you may want to have a facing on the back of the face fabric. You can get a load of info at www.chfschool.com.
Connie Sikora