I also mixed and matched a rod with different curtain rings. I found when looking for rings it would specify on the package the rod width it would work for. The rings you describe don't sound quite big enough. I also like the look of the larger ring on the rod instead of a snug fit. I also found it tricky to find rings in black, many stores would have an ORB, which in some cases looks black. I actually found my rings from Home Depot. Lowes also had a nice selection as did JCP. Here are my rod/rings for reference:

{{!gwi}}

I think I saw the style you are looking for with the little loops at either Lowes and/or JCP.

Thanks, valinsv! Your curtains look beautiful. How did you get them to make such nice neat folds??

ORB is frustrating. My window frames are a very dark brownish-black metal - pretty much what I would expect ORB to look like. But all the ORB rods I've seen look pretty much jet black to me. So I'm not sure what the difference is in buying ORB vs. black, or even if they're mix-n-matchable.

The difference between ORB and black can be a subtle one and not all ORB looks the same. However, in the light I find that ORB can have a slight brownish cast to it whereas in my pic above, you can see the cooler, silverish sheen of the black rod. If I found the right rings for the right price, I would've matched them up and had been considering some ORB rings from JC Penney's when I had found the ones at HD when purchasing other items. The price of rings can really add up so it's good to shop around. I needed a long rod so my choices were a bit limited, but I did see several nice ones at Lowes. I wanted the Pottery Barn look, without the Pottery Barn price so I checked their website for specs and tried to get similar elsewhere. Curtain rod was from JC Penneys. As for the folds, these are drop cloth drapes, I just ironed them and then folded the tops over so that it was double thickness and then arranged the folds after hanging the way I wanted them. I think the fold gives the fabric extra stiffness to hold the fold.

I have spray painted rings with great success with Rustoleum spray paint. As to ring size, I'm thinking it should be about 1 1/2 inches.