You cut your first name sign. You watched it come off the table, you picked it up, and the middle of the O was on the floor under the slats. So were the two little islands out of the B, and the triangle out of the A.

Every one of those pieces is called a counter, and the small strips of metal that hold them in place are called bridges. Putting them in is one of the two or three things that separates a cut file that works from one that just looks right on the screen.

Here is how to do it in Inkscape, where to put them, and how big to make them.

A font was drawn for paper. On paper the middle of an O is just white space — the paper is still there holding everything together.

Steel has no paper. When the torch finishes tracing the inside circle of an O, that disc of metal is completely separated from everything around it and gravity takes it. Same for the closed part of an A, B, D, P, Q, R, e, o, a, g, and the middle of a 0, 4, 6, 8 and 9.

A bridge is a deliberate gap in the cut line. You break the inner path in two places and connect the island to the surrounding metal with a small strip that never gets cut.

Everything below can be done with a plug-in or a fancy font. Do it by hand once anyway, because once you understand what a bridge actually is you can fix any file anybody sends you.

1. Convert the text to paths. Type your text, pick your font, size it, then Path then Object to Path, or Shift+Ctrl+C. Until you do this the letters are still text and you cannot edit their outlines.

2. Ungroup. Object then Ungroup, twice. You want individual letter paths, not a group.

3. Draw the bridge shape. Take the rectangle tool and draw a small rectangle that straddles the inner outline of the letter — half of it inside the counter, half of it in the letter body. This rectangle is the metal you are going to keep.

4. Union it in. Select the letter and the rectangle together, then Path then Union, or Ctrl+Plus. The rectangle merges into the letter and the inner outline now has a gap in it. The island is attached.

5. Repeat. Every counter in every letter. On a long name this is tedious. It is also five minutes.

That is the whole technique. A bridge is not a special tool, it is a rectangle you welded on with a boolean operation.

This is the part that decides whether the sign looks handmade or looks cheap.

Put them where the eye does not go. The bottom of a counter, or the side where a stroke is already thick, reads as part of the letter. A bridge across the top of an O, dead centre, reads as a mistake.

Two per island beats one, usually. One bridge holds the piece but lets it pivot and lift as the torch passes, which is how you get a piece that stands up and gets hit by the torch. Two bridges on opposite sides hold it flat. On a very small counter one is fine.

Line them up across the word. If every letter gets its bridge at the same height, the whole sign reads as a design decision. If they are scattered, it reads as damage.

Follow the natural stroke direction. On an O the thinnest part of the ring is usually at the top and bottom, and the thickest at the sides. Bridging at the thick part hides the bridge better.

The number that matters is your kerf — the width of metal the torch actually removes. That is usually somewhere between 0.04 and 0.09 inches depending on your amperage and consumables.

A bridge has to be comfortably wider than the kerf or the torch simply removes it and you are back where you started.

Working rules I use:

Thicker metal wants a wider bridge because your kerf is wider and because the part weighs more.

Go a little wider than you think on your first run of a new design. A bridge that is slightly too obvious is a sign you can sell. A bridge that burned away is a piece on the floor.

Some fonts are drawn with the bridges already in them — stencil fonts. The counters are already open. Load one, type, convert to paths, and you are done.

It is genuinely the fastest route and there is nothing wrong with it. The limitation is that you get the look of that particular stencil font, and there are not many good ones, so a shop that leans on stencil fonts starts producing signs that all look alike. Learn the manual method and stencil fonts become an option instead of a crutch.

Bridges are for the islands inside letters. Separately, the letters themselves have to connect to something.

On a name sign with a border or a backing plate, the letters attach to the frame. On a cursive name the letters usually already touch each other and the whole word is one connected piece — which is exactly why cursive script sells so well for plasma. On a block-letter name with no border, each letter is a separate part and you either cut them separately and weld them to a backer, or you add a baseline strip connecting them.

Decide which of those you are doing before you draw, not after you cut.

Open the finished file and, one letter at a time, ask: is this piece of metal connected to the piece around it? Follow the outline with your eye. If you can travel all the way around a closed loop without ever crossing a gap, that piece is falling out.

Most CAM software will also show you the parts it has identified. If it thinks your sign is thirty-one separate parts and you drew one word, you have missed some bridges.


[Watch: How to Bridge Letters in Inkscape - CNC Plasma Design Essentials](https://www.youtube.com/watch?v=sg36ZhfLL8w)

Every cut file in the [Tin Man Metal Works store](https://www.tinmanmetalworks.com/hero-theme-store-front) ships with the bridging already done and tested on a real table, in both SVG and DXF. If you want to look at properly bridged geometry before you draw your own, the [free cut file library](https://www.tinmanmetalworks.com/blog/free-cnc-plasma-cut-files) is the cheapest way to do it - open one in Inkscape and look at where the gaps are.

For the whole design workflow in order, the [masterclass](https://www.tinmanmetalworks.com/start-today) covers bridging alongside toolpathing, pricing and everything else that turns a table into a business.

Object to Path, ungroup, draw a rectangle straddling the inner outline, Union it in. Two bridges per island, lined up across the word, placed where a stroke is already thick. Size them 0.10 inches on thin sheet up to 0.25 inches on quarter-inch plate. Then check every closed loop before you fire the torch.