Thank you all for feedback so far. Awesome answers, each one. All the point, many thanks. Looks like the right place to be.
Deraven, indeed, maybe other solutions are possible. The use: for panels in sliding doors, of varying height and width (together with (30586, window rail). In this particular door i would like to make a panel of 1x4x5 or 1x4x6. Obviously, I can make the door panels of 1x4 bricks, but this becomes to heavy and is not elegant. Hence, looking for a 'thinner solution'. I think I can settle for combinations of the panels (4215).
For info, overall project: building a replica of our home apartment,
Thanks again and greetings, Hanas