A set of rulers with a cutout designed for drawing a grid onto fabric such as aida. There are versions for 11, 14, 16, 18, and 20 count fabric. They have the count engraved in the surface to make it easy to tell them apart.
To use, simply line up the leftmost tick mark at your zero point, ensure the ruler is straight by checking that the holes are centered within the ruler's cutouts, and draw along the lines. Bear in mind that if your fabric holes aren't perfectly spaced (e.g. if the fabric is stretched) not all the tick marks may line up correctly and you will have to work in smaller sections.
Each ruler measures up to 50 squares and has tick marks at increments of 5 and 10.
This design was intended for a fabric pen with a 2mm tip, but smaller pens and maybe some slightly larger pens will also work.
The author marked this model as their own original creation.