I did the same with the french door film, unfortunately my windows in the office are almost 7-1/2 feet tall and stacked 3 sections wide. Had to pc it all together, but still works great.You can use the frost king window film, but just get the film and purchase the 3M tape separately. Hog is exactly right here, there is a big difference in quality between 3M and all others we tried. For big windows I got the film sheets made for French doors. They covered our 10' x 5' picture windows without seams.