Rollerball pen Guilloche Black Guilloches - ornamental patterns of fine, engraved lines - originally adorned precious watches and accessories such as the legendary Fabergé eggs. Graf von Faber-Castell uses this traditional jewelling technique to transform the writing instruments in the Guilloche series into true pieces of jewellery: The precious resin barrel is given a filigree pattern line by line and then further refined in manual lacquering and polishing processes. The Guilloche models are available in many expressive colour variations, as well as in a rhodium-plated finish.