Photo to line art

How to make line art from a photo with Stencil AI

Line art from a photo is the same conversion as a stencil, with different decisions afterwards: the line weight has to suit the output, and the export usually needs a transparent background. The split anime portrait on this page shows the kind of result to expect on a stylised subject; a real photograph converts the same way.

Line art vs a stencil: what is the difference?

Line art is a drawing made of lines only. There is no shading, no tone and no filled area beyond the occasional solid black shape. Lines can be open, they can vary in thickness, and they can float free of each other, because nothing has to be transferred or cut. A stencil starts as line art and then follows extra rules. A tattoo stencil needs continuous, closed outlines that an artist can follow with a needle, and it is often mirrored before transfer. A cutting stencil for paint or vinyl needs bridges so that enclosed shapes, the islands, stay attached to the sheet.

That is why an outline that looks perfect as an illustration can be useless on a cutting mat. If the drawing will be cut, read bridges and islands in stencil design or start from the photo to stencil converter page instead. If it will be drawn over, coloured, engraved or stitched, line art is exactly what you want.

AI, hand tracing or vector tracing?

There are three real ways to turn a photo into line art. An AI converter redraws the photo as continuous outlines, drops the shading and closes the shapes, which makes it the fastest route and the only one that copes with soft, low-contrast photos without manual work. Hand tracing in a drawing app means placing the photo on a bottom layer at reduced opacity and drawing every line yourself on a layer above; it is slow, and it gives you every decision. Vector tracing, such as Image Trace in Illustrator or Trace Bitmap in Inkscape, turns a high-contrast bitmap into editable paths, which suits logos and flat graphics and works poorly on photos unless you threshold them first.

Most illustrators combine them: convert with AI to get the proportions, then redraw the parts that matter by hand, or vector-trace the clean AI output when a cutter or laser needs paths. An AI converter redraws rather than copies, so flip the before/after slider on eyes, hands and lettering and correct anything that drifted before you export.

What the editor does for line art

Adjust is where the line art gets its character. Line Weight is the single most important slider here, because a colouring page, a laser engraving and a digital underdrawing all want different thicknesses from the same outlines. Darkness keeps every stroke solid, which matters when the file will be traced by software later. Smoothing turns the slight tremor of a photo edge into the kind of confident line a pen would leave.

Transform frames the drawing. Square crop is handy for social posts and sticker sheets, Free crop for everything else. Rotate straightens a tilted photo, and Mirror is useful when you want the figure to face the other way in a composition.

Ink is the tool line art users open most. Five preset colours and a Custom Color picker change every line at once, and the Paper switch between White and Transparent decides whether the export is a finished image or a layer. Transparent black lines over a colour fill is the classic illustration workflow.

Touch Up is your pen and eraser. Erase removes the specks and the background edges that would confuse an auto-trace, and Draw closes shapes so a fill tool stays inside them. Brush Size goes small enough for eyelashes and large enough to blank out a whole corner.

Choosing a photo for line art

Line art shows every decision the model makes, so the source photo has to give it clear ones. Sharp focus is the first requirement: a soft edge produces a hesitant line. Even lighting is the second, because a strong shadow across a face reads as a shape and can turn into an outline that does not belong there.

Composition matters more than for a stencil. Leave a little room around the subject so the outer contour is complete, and avoid crops that slice through a hand or the top of the head, because those edges become hard straight lines in the drawing. Plain backgrounds convert to nothing, which is exactly what you want.

Side light matters most. It puts a visible edge between the lit and shadow sides of a face, a hand or a flower, and that edge is the line you want. Flat light from a phone flash erases those edges, and backlighting turns the subject into a silhouette with nothing inside it. Skip screenshots and heavily compressed images, since compression blocks turn into jagged edges.

Stylised sources, like the anime portrait example, convert with very little clean-up because the artwork already has flat colour and defined edges. Photographs of people, pets and objects need a minute in Touch Up, mostly to remove background traces and close any outline the light broke. The photo to stencil converter page covers source selection in more detail, and pet portrait line art from a photo deals with fur, whiskers and eyes.

What to do with the line art

For illustration, a transparent PNG of blue lines behaves like a pencil rough: drop it on a layer, lower its opacity, and ink on top. For colouring pages, the goal is closed shapes and no tiny interior detail, so raise Smoothing and Line Weight and erase clutter. For engraving and wood burning, the opposite is true: thin lines and less of them, because every line becomes a burn. Wood burning stencils and pyrography transfer covers the transfer step.

For a colouring page, photos with a few large shapes, such as a pet, a house or one person, make better pages than busy scenes; raise Line Weight a step or two, make sure every region is closed so colour has somewhere to stop, and print fit-to-page. For laser engraving, the software can burn a black-and-white PNG directly in raster mode or trace it to vectors for a scored outline; use heavy, smooth lines and remove any line thinner than the laser's spot size.

For embroidery, the line art is a guide the digitising software follows rather than a finished stitch file. Keep the outlines simple and continuous, because a stitch path cannot jump gaps: fewer, longer, closed lines stitch cleanly, while hundreds of short strokes turn into a mess of jump stitches. For cutting machines, the line art needs to become closed shapes; Cricut stencils from a photo walks through the trace and the settings, and the spray paint stencil maker page explains bridges if the design will be cut as a stencil rather than a decal.

Getting the line weight right for the output

Line weight only makes sense relative to final size. A line that looks fine on the iPhone screen at full width can vanish when the drawing is printed at postcard size, or look clumsy when it is blown up to a poster. Decide the output size first, then set the slider.

A practical check: export, place the line art at its final size in whatever app will use it, and look at the thinnest line. If it breaks up or looks grey, come back and raise Line Weight. If the lines merge into blobs around the eyes or in the hair, lower it or raise Smoothing to drop the smallest strokes.

The same logic tattoo artists use for outline thickness applies to any line art that will be reproduced, and line weight for tattoo stencils explains it with examples. When you need a hard copy, how to print a stencil at home covers the printer settings that keep thin lines crisp.