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TWSBI Diamond 50 Ink Bottle

Regular price $ 25.00
Unit price
Shipping calculated at checkout.

The perfect side kick for any fountain pen enthusiast, the TWSBI Diamond 50 Ink Bottle features a signature filling port that plugs directly into your TWSBI pen. No need to keep dipping your fountain pen into the bottle: simply place your TWSBI pen vertically on the port, rotate the end cap clockwise to feed the ink, and watch the pen fill up with the ink of your choice. Fill them with your favorite inks for a fully customizable writing setup. No mess or spills here!

If you prefer to dip, you can remove the port cap and use the attached funnel to draw ink out of the bottle as you normally would—this multipurpose bottle adapts to your preferences. 

Choose from Black or Red colorways. 


  • Holds 50mL (1.7oz) of ink
  • Measures 3.1" x 2.4" 
  • This is an empty glass bottle. Ink is not included.

How to Use: Take off the nib set. Open the ink bottle cap. Firmply insert pen barrel into the bottle's filling nozzle. Rotate end cap clockwise to fill the ink. Remove the pen and install the nib set. 

Filling All Other Pens:  Open the top and middle cap of the bottle. Insert plastic funnel into the bottle. Close bottle and flip upside down so that the ink flows into the funnel. Open the bottle again and insert your fountain pen into the ink bottle. Wipe and soak off extra ink around nib and feeder area. 

About TWSBI:

With 50 years of experience in pen making, Taiwanese manufacturer TWSBI is beloved for its high quality writing tools at affordable prices. Most of their pens are made with transparent barrels, allowing you to develop your own technique and understanding of a pen's particular inkflow.  

TWSBI's name comes from the phrase "Hall of Three Cultures" or San Wen Tong in Chinese. The phrase San Wen Tong recalls the Hall of the Three Rare Treasures, created by Emperor Qianlong as a memorial to three great masterpieces of Chinese calligraphy, with the character Wen translating to "language and culture." When reversed, the initials of the phrase San Wen Tong transform into "TWS". The last letters "Bi" was added with its literal meaning of "writing instruments". The two segments come together to create TWSBI.

Their mission is to inspire and recapture the romanticism of art and literature…starting with the pen.

Next Day In-Store Pickup Available