How small can embroidered text be?

Our test: one name, five heights, two styles

We asked BobbinBot's engine for the name Anna at 4, 5, 6, 8 and 12 mm, in Block and in Script lettering, on a t-shirt. For each one we kept the verdict, the size that came out, the stitch count, and what an OCR program, Tesseract, read back from the stitch simulation. The self-check was off, so each row shows what that height gets on its own.

All ten drawn at the same scale, 8 pixels per millimetre, so you can compare sizes. Simulations, not photos of thread.

Two things stand out. Every simulation still read back as the name, even at 4 mm, so the letters do form. And script at 4 mm and 5 mm came out exactly the same size, because the script font cannot be made any smaller. The next sections explain both.

Where we draw the line, and why

Our engine marks lettering at 5 mm or less as yellow, with the note “Letters under 5 mm are hard to sew.” That line is a rule in our settings (min_letter_height_mm in config/thresholds.json), and our stitch form does not offer anything smaller than 5 mm. It is a cautious rule, not a sew-out result.

The reason for caution is how letters are stitched. Each stroke of a letter is a satin column: the thread zigzags from one edge of the stroke to the other. The smaller the letter, the narrower each stroke, and the shorter each zigzag. Our checks flag stitches shorter than 0.5 mm (micro_stitch_mm in config/thresholds.json), because many of those in a row can jam the needle. In pictures, our engine sews anything narrower than 1.5 mm as a single running line, because a zigzag that narrow does not cover. Letters come from the font, so they keep their satin and get closer to that limit as they shrink.

A readable simulation does not prove a clean sew-out. The simulation draws every stitch perfectly. On fabric, the thread has thickness, the fabric moves, and small counters like the hole in an a or e can fill in.

What letter height means

When you ask for 8 mm, our engine sizes the font so its tallest letters are 8 mm. We measure every font the same way, on a stitched “Sofia”, whose S and f are among the tallest letters (config/fonts.json). A name without tall letters comes out shorter than the height you asked for. That is why Anna in script, asked at 12 mm, is 9.2 mm tall.

Every font also has a smallest and a largest size it can be scaled to, set by the font itself. Below its smallest size the font stays at that size, which is what happened to script at 4 and 5 mm.

Making small text sew better

On a towel, our sew-out kit adds a water-soluble topping over the terry (config/items.json). Try it with the towel preset in our text tool.

• Choose block lettering for small text. Our block font goes smaller than our script font.
• Keep it short. One name sews better than a sentence at the same height.
• Go up a step if you can: at 6 mm our checks are green, and 8 mm gives every letter more room.
• Use one color for small text, so there are no color changes and trims between tiny letters.
• Check the finished file in the free checker, which lists tiny stitches and long jumps.
• Sew a test on scrap of the same fabric first, with the stabilizer you will use.

What we have not tested yet

Everything on this page comes from our engine: the files it wrote, the simulations it drew and the checks it ran. We have not yet sewn these test names on fabric. When we do, the photos and what we learn go here, and the date at the top changes.