As to the gathering, you use what's called (here anyway) "header tape", which is a wide cotton tape with holes in it at regular intervals to insert special pronged curtain hooks. The prongs are what makes that type of gathers at the top. You can have the curtains open or closed (and in your photo they are clearly normal window covering width curtains that have been pushed open as far as they will go.).

Fabrics I would go to the store and see what drapes and hangs well that I liked.

The top of the draperies are drapery pleats,,made with pleater tape--as colleenoz says, the pleats are made by sliding the pronged hooks into the tape after having stitched it to the fabric. The bottoms on the floor is simply called "puddling"---excess length of draperies. Certainly you can close (and drag the "puddle" across the floor)...or you can leave them open all the time for show---in a room where no one can see inside when you're in your p.j's.

Thanks so much! That helps a whole lot.

What would that kind of fabric be? It is not linnen probably. Isi ti s mix of cotton and linen or just a heavy cotton? Does this kind of fabric has a specific name?

I have never seen a cotton that heavy, but I do not have experience with fabric decorating

To me, it would be very cumbersome working with large, heavy lengths of fabric, sewing on pleater or header tape, lining, etc. Instead I suggest scouting local stores that carry draperies, and find a fabric and color that speak to you. Then buy your selection in a length that's "longer than needed" so that the excess can puddle on the floor and achieve the effect you want.

Here's an example from Bed Bath & Beyond. There are other styles and other stores too.

https://www.bedbathandbeyond.com/store/product/valeron-estate-cotton-linen-window-curtain-panel/3256544?categoryId=12198

I don't think those drapes are made with pleater tape. I think it is a wide pinch pleat. I don't know the technical name for it but I saw that header years ago when I was researching how to make pinch pleated drapes without pleater tape. Simply put it is a single wide pinch pleat. Look in the top right corner of this site

https://www.pinterest.ca/pin/111182684523313208/

Making your own pinch pleats is relatively simple but requires a lot of measuring. If you are making the wide pinch pleat and want it to stand out from the drape I'd use buckram for the header

Well I did some research and they do sell pleater tape to make that pleat. As for fabric I don't think you have to go to that heavy material. Any drapery fabric that has enough weight to fall straight down will work.

For opening & closing, I would avoid using puddled drapes. I have not made drapes with that type of header shown in your photo, but it's really pretty. Looks relaxed & casual. Maybe it's called a "Frill Top Header"? I found a link to something that looks similar. I would guess that buckram might not be used in this case because the header looks so soft/relaxed. The fabric may be a cotton or linen that has been lined.

See the frill top header on this link:
Kate Forman

Laurie, the frill tops are too pretty, I love the look.

Good point about not doing puddles for curtains that need to be closed, I did not think of that.

I would love to buy curtains instead of sewing them and also I have to remember that cannot make everything by myself. Thanks for the link Juneroses! Its is just my window is huge, so I would possibly need a wide curtain and it would lost more than in my budget.

I think I definitely use this curtains for living room, not bedroom.

Thanks so much for your help!

Here is another link that relates to this post. This site uses the term "gathered heading with stand up frill". It has good photos and descriptions of how to use the gathering tape. Jones Design Co

The person in the above link used Ikea curtains , cut off the top tabs, and sewed a "deep hem" (header)....then proceeded to use the tape.

I would love to try this some day.

It looks very similar, looks pretty. I will try one the frill on the bedroom and the more formal one in the living room and will post the pictures

That sounds great. Look forward to seeing the pictures and hearing about the process you used!

Hi! Consider using canvas drop cloths! Love the directions on Jones Design from Laurie! mb