Medieval ink was typically charcoal-based and used gum as an adhesive. Black was the color of choice; red was employed for embellishments and corrections. Another type of ink was produced from an acid-metal solution and become more popular in the later Middle Ages. The manufacture of ink required a mortar and pestle for grinding the raw ingredients. Ink was stored in a small reservoir called an inkhorn. Screw-on lids made these inkhorns portable. Quill pens were usually attached to inkhorns by a string or chain.
A feather plucked from a goose is not immediately useful as a writing instrument; it must undergo preparation for this use. The writing end of the quill was tempered with heat to reduce brittleness. After that, a slit was carefully made so that the quill would hold ink. Most or all feathers were removed, as these only got in the way of the writing process.
The writing surface of choice for medieval scribes was parchment, which was made by soaking animal skins in a water-and-calcium solution after removing all fat and hair. The mineral bath strengthened the finished product. The material was stretched and dried, and any remaining flesh was scraped off. Parchment was an excellent writing surface, but, because of its high production cost, paper supplanted it by the end of the Middle Ages.
A medieval writer always kept a knife at hand; it was used to quickly erase mistakes. Parchment sometimes had bubbles and contours, and a scribe used a knife to hold the material flat against the desk. Knives were also used to sharpen or adjust the quill pen tip. If the pen stopped holding ink, its tip could be reshaped with a sharp knife; a second extremely sharp knife may have been reserved solely for this purpose.