I know nothing about sewing, so I can't really help with that part of your question. However, my solution was a little different than yours and I'll post it to give you another option. I had a roll-down solar shade with a 5% openness factor (blackout is also available) on my sliding doors in a former home.

I had a simple box valance made to hide the top and covered it with the drapery fabric. The draperies were pinch-pleated and hung on a rod above the door, but still behind the valance which allowed me to use a non-decorative rod, offsetting some of the cost of the valance.

During the late afternoon, I could roll down the shade and block out much of the sun, but still have some natural light in the room. At night, I could draw the draperies across the doors to create a cozier environment.

I made panels, used ring clips, and just clipped the separate blackout liner to the clips along withe the drapes. just make sure your rod has extra support..I used barkcloth and with the liner it was so heavy that over time the rod bent. And you're right, I don't like the "flat" panel when they are closed either.

Thanks for the replies and help. I think I will go ahead with the pinch pleats and add the blackout lining separately. I will let you know how they turn out. Thanks again!

I have blackout drapes on my french doors and they are not bulky. Just make sure you use a single layer of the lining in the header, don't fold it over. Also, you might consider less fullness in your pleats (or two finger pleats) for a tighter stack.

sallymo - Do you also have buckram inside the header (in addition to the single layer of blackout)?

I was wondering if buckram would be needed to keep the pleats (pinched pleats in the header) crisp/stiff enough to work with.

I am thinking the blackout (single layer) and fabric (double folded) may be all that is necessary for the header but I'm not sure.

No I didn't use buckram, I forgot to add that!! Thanks for bringing that up. My pleats are a little more casual, although they usually stack back even enough, but not always perfect. Definitely the buckram adds some bulk.

Kaatluvr how did it go with your liner? What did you end up doing and do you have any recommendations?