His drapery shop

In his letters, Leeuwenhoek never made any reference to how he made a living, especially in the period before he began to work for the city of Delft in 1660.

We have two bills of sale to support the contention that van Leeuwenhoek sold all the materials for making clothes: fabric, especially linen, and affordances like buttons and accessories like ribbons.
These documents were discovered in the effects of an estate. They ...
In addition to this direct evidence, we have two other things. From ages 16 to 21, van Leeuwenhoek lived in Amsterdam and apprenticed with cloth merchant William Davidson. When he returned to Delft, he bought a house on the Hippolytusbuurt from Johan Leiftingh, an apothecary. So the house was already set up for a shop.
The final bit of evidence is the letter of _____ when Leeuwenhoek writes of ___ of his draaibank sticking through a slot the made in the wall of his "comptoir", which is the word often used for he office part of a shop where the money and records were kept. By ___, perhaps Leeuwenhoek had already converted the comptoir of his draper's shop into the workroom for his metal and glass work.