I hope I understoot the word Undulating (never heart it before) good enough for this ZT.
The next ZT I drew in my little ZT book on page 16
Inspired by an antique key.
Dark and light brown Micron and shaded with colored pencil.
The background tangled with "Pixioze", the new tangle from Margareth Bremner and "Sevaw" from Emmy Chen.