In the mid-20th century, the felt-tip pen evolved with the introduction of nylon and polyester fibers for the tip. These materials were more durable and consistent than the felted wool used in early models. This development led to more reliable and longer-lasting markers and pens, which became widely used in offices, schools, and for artistic purposes.

The improved felt-tip pen offered poets and artists a new tool for creative expression. Its bold, colorful, and expressive lines were ideal for visual and concrete poetry, where the typography and layout are as important as the words. The durability and consistency of the nylon tip made it a reliable tool for creating posters, signs, and other visual works, expanding the possibilities for poets to engage with the public in new and visual ways.