Plasma cut files start by throwing detail away
Plasma is a blunt instrument, and that is the whole design brief. An arc blows a channel through the plate, and that channel has width — how much depends on the current, the consumable and the steel, but it is never nothing. Detail narrower than the channel does not come out thin. It comes out gone: the two sides of a hairline meet, the sliver drops through, and a crisp serif on screen is a nub on the bench.
The second tax is the pierce. Every closed loop that is not the outer profile has to be started by punching down through the plate, and a pierce costs dwell time, a spray of molten metal and a share of the consumable's life. A silhouette with one outer edge and six interior openings is a short program. The same silhouette carrying two hundred pinholes — the kind a traced photograph produces without anyone asking — is that shape an hour later, with parts to change afterwards. Counting loops in the preview is the cheapest check in the shop.
So simplify first and convert second. Two colours is the setting that does it: the image collapses to one shape on one background, and what comes back is a single profile with only the openings your artwork genuinely has.
Drop an image here
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How it works
- Flatten the artwork before uploading — thicken hairlines, close near-touching gaps, delete anything you would not want to pierce.
- Add the PNG, JPEG or WEBP, one image per conversion, and set Colours to 2 so the trace returns a single profile.
- Tick DXF, leave Shape stacking on Cut-outs, and type the finished width and height in millimetres.
- Read the preview and count the interior loops: each one is a pierce you will pay for.
- Sign in with Google (free) to download; the header names millimetres, so CAM opens the drawing at scale — add kerf offset and lead-ins there.
Who this is for
The jobs behind this search are mostly steel and mostly signs: a gate name panel, house numbers, the cut-out sides of a fire pit, a bracket sketched on paper, a workshop logo for the roller door. The artwork turns up as a picture — a phone photo, a clip-art silhouette — and the table wants boundaries instead.
Be clear about what the file does not carry. It holds the outline as drawn: no kerf compensation, no lead-ins, no lead-outs, no pierce points chosen for you. Those belong in your CAM or nesting program, which knows the material and which side of the line to stay on. The contours are measured off pixels by a geometric tracer, not recovered from an engineering drawing, so if the bracket must bolt to something, check it against your own measurements first.
Settings we suggest
Colours: 2. For a silhouette that is not a compromise but the right answer: one boundary between shape and background, one layer in the drawing. Raise it to 3 or 4 only when the panel really has regions you treat differently. The axis reaches 64, and every step up invents loops, which here means pierces.
Shape stacking: Cut-outs, always. Interior openings arrive as their own closed loops nested inside the profile, which is how a nesting program tells part from scrap. Stacked writes overlapping shapes that share edges, and a shared edge gets cut twice.
Size: fill in both millimetre fields. What you type is applied to the DXF and is the only way to be certain of physical dimensions, since images above 1.5 megapixels are downscaled before tracing. Left blank, coordinates follow the pixel grid at 96 px = 25.4 mm. In both cases the drawing states its unit in the header, $INSUNITS = 4, so the nesting program is not left to guess.
What lands in the file: DXF R2010 (AC1024) — LWPOLYLINE runs for straight sections, degree-3 SPLINE for curves, one layer per traced colour named FILL_ plus its hex value. The exporter never writes a HATCH, so every shape is a boundary rather than a solid — the form a toolpath is generated from. Draw style and grouping do not reach this output.
Questions
How fine can the detail be before plasma eats it?
A machine question rather than a file question: the width of the cut depends on the process, the current, the consumable and the plate, so your own cut charts hold the figure. What follows from it is simple — a feature narrower than the cut disappears, and small openings get unreliable as the plate thickens. Hunt the artwork for anything thinner than that number: hairline serifs, single-pixel strokes, two letters that almost touch. Fatten them before you convert.
Do I offset for kerf before or after converting?
After, in your CAM. The outline is written exactly as the artwork drew it, because which way an offset goes depends on whether a loop is part or hole, and how far depends on settings this converter never sees. Everything stays editable — LWPOLYLINE vertices, SPLINE control points — so your nesting software can offset, add lead-ins and order the pierces.
My file came back with hundreds of tiny loops. What went wrong?
Nothing went wrong; the source was too rich. Photographs, halftone-printed logos and soft anti-aliased edges all hold small colour regions, and at a high colour count each becomes a contour with a pierce attached. Convert again with Colours at 2, and if islands survive, clean the artwork up and convert once more.
Which programs open it, and why did my panel import at the wrong size?
It is DXF R2010, the AC1024 header — AutoCAD 2010 and later, Fusion 360, LightBurn, FreeCAD and Inkscape all read it, and most CAM and nesting front-ends import DXF. Size is a question of what you typed rather than of units: coordinates sit at millimetre scale and the header says so ($INSUNITS = 4), which is what stops a front-end assuming inches and blowing the drawing up 25.4 times. Type the finished width and height in millimetres before converting — a 900 mm gate sign is then written 900 mm wide; leave the fields blank and the panel arrives at whatever the traced pixel grid works out to.
What does it cost, and what are the limits?
It is free and nothing is watermarked. Preview the traced result first; a free Google sign-in then releases the DXF download. Signed out you get 10 conversions per hour, signed in 60 per hour and 300 per day. One image per conversion, as PNG, JPEG or WEBP, up to 25 MB and 40 megapixels. Logos and stickers typically convert in 3–12 seconds in our local measurements; fine-line or noisy images take longer, and a conversion that does not finish within 60 seconds stops and suggests fewer colours or a smaller image. Download links expire after 1 hour, and uploaded images and generated files are removed by an automatic 1-day deletion rule.