Diamine Inkvent Purple Edition's Bah Humbug is a 50mL bottled Chameleon and Sheen ink designed for use with fountain pens. It is one of 25 distinct shades of purple included in the 2023 advent calendar.

The Diamine Inkvent Purple Edition series features various categories, including Standard, Sheen, Shimmer, Scented, Chameleon, and the newly introduced Star Bright.

Standard inks: Cashmere Rose, Early Dusk, Jacaranda, Velvet Emerald, Glacier, Weeping Willow, Walnut and Fireside Snug.

Shimmer inks: Masquerade, Merry & Bright, Lavender Frost, Blizzard, Tinsel and Sugar Snap.

Chameleon inks: Fortunes Gold, Nightfall, Buck's Fizz, Moon Beam, Bah Humbug, Rainbow's End, Astral and Tranquility.

Chameleon & Sheen ink: Raise a Glass.

Scented inks: Cinnabun and Sweet Dreams.

Due to the high quality of the inks, they are suitable for all brands of fountain pens.