help

The studio is where images become line art: the left pane feeds and tunes the image, the middle shows the render, the right pane manages pens and exports. Every control in the app has a tooltip — hover (or long-press) it for a hint in place. This page is the longer version.

the RSTR studio on desktop, its sections outlined and numbered — 1 source & adjustments, 2 video, 3 segmentation and 4 lines on the left, 5 presets, 6 layers, 7 export and 8 stats on the right, the render in the middle

1 image — load a picture or video and tune it before tracing.
2 video — frame rate and export window, shown while a video is loaded.
3 segmentation — how the image is carved into tonal regions.
4 lines — pen width, how ink turns into line spacing, and the optional hand-drawn wobble.
5 presets — randomize everything, or save and share complete looks.
6 layers — one pen per layer: color, channel, hatch angles, overrides.
7 export — output width and the SVG, PNG and frame-sequence downloads.
8 stats — render numbers and the estimated plot time.

image

browse / drop: Load an image or video from your device — or drop it straight onto the render. Nothing is uploaded; all processing happens in your browser.
input thumbnail: Hold it down to peek at the input with the adjustments below applied.
brightness / contrast: Brighten or darken the image, and push contrast around mid grey, before segmentation.
gamma / key: Midtone curve — above 1 lifts the midtones, below 1 keys them down.
saturation: Uniform color saturation; 0 turns the input greyscale.
vibrance: Saturation boost weighted towards muted colors, so it won't blow out what's already vivid.

video

supported formats: Whatever your browser can decode — MP4 (H.264) and WebM play everywhere. HEVC (H.265) videos, like the .mov recordings phones make, don't decode in many browsers; the studio will tell you when that happens. Convert those to MP4 (H.264) first — QuickTime's export, HandBrake, or ffmpeg -i input.mov -c:v libx264 -pix_fmt yuv420p output.mp4 — and load the result.
output fps: Frame rate the video is sampled at — fewer frames per second means fewer, smaller files.
frames: The exported frame window (first – last). The timeline over the render shades this range; scrub it or step frame by frame to preview any moment with the current settings.
frame sequence export: Renders every frame in the window and downloads one zip — plottable SVGs, images (png, jpeg or webp with quality and scale controls), or both.

segmentation

Segmentation carves the image into regions of similar tone — the shapes the lines will fill.

algorithm: Watershed follows tonal basins, posterize bands intensities, k-means clusters them, and SLIC carves compact superpixels.
resolution: Grid resolution the image is sampled at — more cells, more detail, slower renders.
smoothing: Blur passes before segmentation — higher means fewer, larger regions.
superpixel size / compactness: SLIC only: superpixel spacing in grid cells, and how strictly they stay grid-like versus following image detail.
tolerance: Maximum intensity difference for merging adjacent regions.
min region size: Regions with fewer cells get absorbed into a neighbour.

lines

pen width (mm): Physical line width used for rendering and spacing math. Layers can override it.
ink gamma: Perceptual weight on ink intensity before it becomes line spacing.
ink boost: Coverage multiplier — above 1 pushes dark regions into overlapping lines.
ink threshold: The band of ink a region must fall in to be hatched. The low bound is a high-pass filter — regions holding less ink stay empty; the high bound is a low-pass filter — regions holding more ink stay empty too (leave it at 1 to keep every dark region). Narrow the band from both ends to isolate the midtones.
spacing (mm): Nominal min–max line spacing. Each region lands somewhere in this range based on its ink: dense lines where the image is dark, sparse where it's light.

hand-drawn lines: Swap the perfectly straight hatch lines for organic, hand-drawn-looking ones. Off by default — and off means untouched: the classic ruler-straight output stays exactly as it was. When on, the same wobble flows through everything consistently — preview, SVG and PNG exports, frame sequences and the plot-time estimate (squiggly lines are longer, so plots take a bit more time). The wobble is deterministic: the same settings always draw the same squiggles.
squiggle (mm): How far a line may wander from perfectly straight — the squiggliness. Lines keep their exact endpoints and short strokes stay steadier, so regions keep their shape.
wave (mm): Distance between direction changes along a line — short makes a nervous scribble, long makes lazy waves.
variation: Rerolls the wobble pattern without changing its character.

layers — one per pen

layer basics: Each layer is one pen: pick its color, name it, toggle it, reorder with ▲▼ (layers draw top to bottom). The name becomes the layer label in the exported SVG.
channel: Which part of the image drives the layer's ink: cyan / magenta / yellow (the print channels), key / darkness, red / green / blue, or (inverted) luminance. "Match pen color" instead derives the channel from the layer's pen color.
angle min / max: Hatch direction range — every region picks its own angle within it, based on the region's shape, so one layer never looks mechanical.
overrides: Pen width, the threshold band (low / high), spacing, ink gamma and ink boost can be set per layer. Empty fields inherit the global lines values (shown as grey italics); "clear overrides" resets them all.

presets & randomize

randomize: The dice rolls all segmentation, lines and layer settings. "Stick to built-in presets" limits the roll to ink + pen combinations that physically exist, so the result stays plottable.
presets: Apply a built-in look, or save your current settings under a name — saved presets live in your browser. A fresh visit opens on a random built-in.
export / import .json: Move settings between browsers or share them as a small JSON file.

export

width (mm): Physical output width — the height follows the image aspect.
fit on page: One tap sets the width so the art fits a standard sheet — A6, A5, A4 or A3 — within the margin below. The page is turned to match the art: wider-than-tall art gets a landscape sheet, taller art a portrait one, and anything square-ish defaults to portrait.
margin (mm): The border kept clear on every edge of the sheet when fitting to a page. Defaults to 10mm.
↓ SVG: A plottable SVG with one layer group per pen, ready for plotter software.
↓ PNG: The current render as an image — for screens, sharing and regular printing.
⚡ order this plot: No plotter? I'll plot it for you — real pens on paper, shipped flat-packed with tracking, shipping included in the price. Orders are limited to the inks in the built-in presets and sizes up to A3; the order dialog tells you if a design needs adjusting. Only the exported SVG — the lines to draw — is sent with your order, never your image, and it's used solely to produce your plot.

stats & plot time

grid / regions / lines / render: The sampling grid size, how many tonal regions segmentation found, how many hatch lines were drawn, and how long your browser needed to compute the render.
plot time: Estimated plotting time on an AxiDraw-style machine (saxi's motion model): drawing, travel and pen lifts — hover it for the per-pen breakdown.
plotter settings: The motion profile behind that estimate: pen-up/-down speeds and accelerations, cornering, pen lift/drop pauses and the join radius (lines closer than this are drawn without lifting the pen). Match it to your machine, or reset to saxi's defaults.

prep — /prep

the prep tool on desktop — a studio export placed on an A3 page, with the paper outline, calibration block and page boundary around it

The plot prep tool takes an exported SVG and dresses it for the machine.

output page: Pick the page size and orientation the plotter will see; drag the artwork (or use the offsets) to place it.
paper outline: A rectangle marking where to place the physical paper — sized to the artwork or a fixed format, plus margin.
calibration markers: Rulers, a verify circle and one line pair per pen, so multi-pen plots line up. Drag the block anywhere.
page boundary: A rectangle around the full output page.
add reversed layers: Duplicates every artwork layer with the same lines running in the opposite direction — each line gets plotted twice for denser ink. Works on the studio's hand-drawn wobbly lines too: every squiggle is retraced point for point, just backwards.
export SVG: Downloads the decorated SVG with everything on its own (Inkscape-compatible) layer.

classic — /classic

the classic app on desktop — a finished multi-color line render next to its resolution, grouping and fill controls

The original RSTR, kept around for nostalgia (and because it still makes nice plots). One image, one layer, multiple pens. The algorithm that started it all.

good to know

private by design: Images, videos and settings never leave your device. The one deliberate exception: ordering a plot sends the exported SVG — the drawn lines, never your image — along with your order, and it's used solely to produce that plot.
works offline: RSTR is an installable web app — once visited, it keeps working without a connection.
settings persistence: Your settings are remembered in this browser from the moment you first edit them — until then, every visit rolls a fresh random preset.
real ink colors: The palettes behind the randomize button are sampled from real fountain-pen inks, so a random roll always lands on colors you can actually plot with. They're based on the ranges from De Atramentis, Octopus Fluids and Rohrer & Klingner.