Chartres Blue Music nib: You can write thick lines vertically and thin lines horizontally, and you can write a variety of characters such as sheet music and calligraphy This is the first fountain pen which has our unique 'Slip & Seal' mechanism in a pen with a screw-type cap. Thanks to this innovation, currently being patented, it is possible to have a screw-type cap with complete airtightness. 14kt gold nib. Go see in the 'Specifications' section below the PDF file for more information.