Flo-Master Ink Cartridge

Flo-Master was known for their refillable pens and markers. This cartridge was catered towards felt-tip pens. 

It comes in a brown cardboard package. The package has a cutout on the front, displaying the front of the cartridge. The cartridge itself has red and white horizontal lines. The Flo-Master logo has a brushstroke design. Their selling point has cursive writing, and everything else has sans-serif text.

Cushman & Denison were the original founders of Flo-Master, but they were later bought by The Esterbrook Pen Company in 1953 (1) and then later merged in 1960 (2). Earlier ink cartridges would have Cushman & Denison branding (1951–1953), and later cartridges would have Esterbrook branding (late 1953 and later). 

Flo-Master had eight different colors available: purple, red, blue, yellow, brown, orange, green, and black (3). The colors were also blendable.

Flo-Master had three separate products: transparent, opaque, and cleanser. Transparent is for general purpose marking on most light colored surfaces and is permanent on porous and painted finishes. Opaque was for non-porous surfaces like metal, glass, or plastic. Opaque was also weather-resistant. Because Flo-Master's ink is extremely difficult to remove off hands and clothing, they also provided a cleanser that could be used to remove ink from non-porous surfaces and clean felt tip pens.

In the 1950s, Flo-Master was initially used for calligraphy purposes such as writing signatures (4). Later, it was incorporated into felt-tip markers. They were versatile because of both opaque and transparent inks. Any surface can be utilized with them. In the later years Flo-Master was the preferred choice of ink when creating psychedelic light shows. About ten years later (1970s), Flo-Master was also being used in graffiti art, mainly for tagging (5).

Since Flo-Master had lead in their ink, the product was discontinued because of regulatory issues (5).

Sources:
1. Unknown, Author. “The Esterbrook Pen Company: From Cornwall to the Moon and Back...” Web log. The Hamilton Pen Company (blog), October 31, 2020. https://www.hamiltonpens.com/blogs/articles/the-esterbrook-pen-company-from-cornwall-to-the-moon-and-back. 

2. "1967 - Esterbrook history merge with Venus camden newspaper" Newspapers.com. Courier-Post, September 26, 1967. https://www.newspapers.com/article/courier-post-1967-esterbrook-history-m/18986483/.

3. "Flo-Master Sketching Techniques." 1950.Design 52 (1) (Oct 01): 18. https://stats.lib.pdx.edu/proxy.php?url=https://www-proquest-com.proxy.lib.pdx.edu/scholarly-journals/flo-master-sketching-techniques/docview/1296370604/se-2.

4. Esterbrook. “Instruction Sheet,” 1950. http://www.esterbrook.net/images/ephemera/diplessfront.jpg. 

5. “REVOLT INTERVIEW.” Revolt interview @149ST, 2003. https://www.at149st.com/rvlt2.html.

6. Dignam, Timothy, Rachel B. Kaufmann, Lauren LeStourgeon, and Mary Jean Brown. “Control of Lead Sources in the United States, 1970-2017: Public Health Progress and Current Challenges to Eliminating Lead Exposure.” Journal of Public Health Management and Practice 25, no. 1 (November 30, 2018): S13–22. https://doi.org/10.1097/phh.0000000000000889.