A painting application built for one thing above all others: latency. The shortest possible path between a pen moving and pixels changing.

Paints on the GPU · reads brushes from MyPaint, GIMP, Krita, Photoshop and Clip Studio · opens Krita, Clip Studio and Photoshop documents · saves to OpenRaster

Early days. Painting, layers, brushes, documents, selections, transforms, text and settings all work on desktop. There is no mobile build yet, and no shape tools. What is not there yet is honest about the rest.

Install

Umber 0.1.6. Take the file for your system, or browse the release itself for the notes and the checksums.

Your system	x86-64	ARM64
Windows	Installer	Installer
macOS	.tar.gz, one universal binary with both slices	(the same file)
Debian, Ubuntu, Mint	.deb	.deb
Fedora, RHEL, openSUSE	.rpm	.rpm
Arch	.pkg.tar.zst	not built
Any other Linux	AppImage, one file with nothing to install	AppImage
Flatpak	.flatpak bundle	not built
Windows, .msi to deploy	.msi	.msi
Windows, no installer	.zip	.zip
Linux, no package	.tar.gz	.tar.gz

The .deb and .rpm add the Spillebulle archive as they install, so apt upgrade or your usual system update carries Umber along with everything else. Nothing to configure.

To add the archive first and install from it, or on a machine that installed Umber before 0.1.5, on Debian, Ubuntu, Mint and Pop!_OS:

curl -fsSL https://spillebulle.github.io/packages/spillebulle-archive.asc \
  | sudo gpg --dearmor -o /usr/share/keyrings/spillebulle-archive.gpg
sudo tee /etc/apt/sources.list.d/spillebulle.sources >/dev/null <<'EOF'
Types: deb
URIs: https://spillebulle.github.io/packages/deb/
Suites: ./
Signed-By: /usr/share/keyrings/spillebulle-archive.gpg
EOF
sudo apt update && sudo apt install umber

On Fedora, RHEL and openSUSE:

sudo rpm --import https://spillebulle.github.io/packages/spillebulle-archive.asc
sudo tee /etc/yum.repos.d/spillebulle.repo >/dev/null <<'EOF'
[spillebulle]
name=Spillebulle
baseurl=https://spillebulle.github.io/packages/rpm/
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://spillebulle.github.io/packages/spillebulle-archive.asc
EOF

You need a GPU with Vulkan, Direct3D 12 or Metal, which is essentially any machine from the last decade. The Linux packages pull in the libraries Umber opens at runtime, so your package manager handles the rest.

Umber checks for new versions when it starts and shows you the release notes before anything is downloaded. You can turn that off on the first run, or in Settings → General.

Brushes

258 presets ship with Umber, grouped by what they do. Pencils, inks, markers, charcoal, paint, watercolour, airbrush, blenders, erasers, texture, foliage, effects. Not by which pack they came from.

Every row draws a real stroke made by the real brush, with a loop and a taper in it, so a rake, a chisel or an angle-following brush looks like what it is instead of like a flat bar.

196 are the whole of mypaint-brushes 2.0.2. Another 56 come from CC0 and CC-BY Krita packs: 32 of those stamp a bitmap tip rather than an ellipse, and 6 paint through the author's own paper texture. Six are Umber's own. Each keeps its author and licence.

Blenders work. A smudging brush picks colour up off the canvas and carries it, and scrubbing back and forth blends its own wet paint. A brush can carry its own blend mode, so a marker multiplies into the paper and a highlighter screens, without putting the layer they land on into that mode.

Bring your own

Import brushes… reads nine formats:

Format	From
.myb	MyPaint
.gbr, .gpb	GIMP and Krita stamps
.gih	GIMP animated brushes, one preset per cell
.vbr	GIMP parametric brushes, reproduced exactly
.kpp	Krita presets
.bundle	Krita resource bundles: a whole pack at once, tips and all
.abr	Photoshop 1, 2, 6.1 and 6.2
.sut, .sutg	Clip Studio Paint sub-tools, a group arrives whole
.ron	an Umber library

A brush leaning on something Umber cannot render is imported anyway, and you are told what was dropped. An approximation of a brush you chose beats a refusal.

Make your own

New brush starts from scratch, and any brush can take a bitmap stamp: one from your library, a picture you import, or one you draw yourself on a canvas Umber sets up for it. Stamps and paper textures have a library of their own, and a paper is previewed tiled so you can see whether its edges meet.

The editor reaches every field a brush has, across six sections: Tip, Dynamics, Inputs, Scatter, Texture and Blending.

Pressure is not the only thing driving them. Speed, how far into the mark you are, direction and a throw of the dice per dab can all reach size, opacity, hardness, scatter, ellipticity, angle and colour.

Change one mid-painting

Brush tweaks puts six rails where you can reach them while a picture is under way. Size and opacity are above the canvas already.

All eight take a keyboard pair too. They change the brush in your hand and not the brush you saved, so picking any brush puts its own settings back.

Layers

Blend mode, opacity and visibility, plus:

• Masks. Greyscale coverage that hides and reveals without touching a pixel. Paint the layer or paint its mask; the eraser reveals.
• Clipping. A layer that only shows where the one below it does.
• Locks. No strokes, transforms or clearing until it comes off, and the controls go quiet rather than ignoring you.
• Link groups. Up to six colour-coded sets that move through the stack together.
• Folders. Group, nest, fold shut. A folder's eye and lock reach everything inside it, and it travels with its contents.

Every row shows what is actually on that layer, scaled to fill the chip rather than the whole canvas shrunk into it, so a sketch on a large canvas is still legible. Tick as many rows as you like and show, hide, lock, link, group or delete them all at once.

Drag a layer sideways as well as up and down to nest it. A dashed outline shows where it lands, and at what depth, before you let go.

Colour

Four ways to pick one. The triangle and the square inside the hue ring can each be turned to whatever angle you like to work at, and each keeps its own.

Wheel, triangle	Wheel, square	Saturation / value	Sliders

A fifth mode, Harmony, marks the complement, triad, either tetrad, analogues or split-complement of the hue you are on and lets you take one with a click. The angles are the RGB colour wheel's, so the complement of blue is yellow here rather than the orange a paint-mixing wheel gives you.

The Palette module keeps the colours you want to come back to. Click a slot to store what is in hand, and save a whole set into a library. A pencil in the header unlocks adding, renaming and rearranging, so a colour is hard to lose by accident.

Palettes are plain GIMP .gpl files in a folder of their own, so anything that reads them can read yours. Umber also opens .ase, .aco, .pal, .hex and Paint.NET's .txt, and there is a box you can paste a list of hex codes into, which is what a Coolors link or a palette copied out of a chat actually is.

Text

Type in any font on this machine and place what you set on the canvas, where the transform tool moves, scales and turns it before it goes down. A text layer stays text: reopen the document and you can still fix the typo.

Fonts	every one installed, plus a folder of your own if you point Umber at one
Shaping	kerning, ligatures and mark positioning, so a word joins up rather than coming out as loose letters
Lines	break where you break them; nothing wraps on its own yet
Set	family, style, bold, italic, colour, size, line spacing, tracking and alignment
Bold and italic	a family's own faces, never a fake slant or a smeared outline. Umber says so when a family has neither

Placing it works exactly like a paste, so Esc abandons it and one undo takes it back off.

Selections and moving things

Select marks out where edits may land: rectangle, freehand lasso, or polygon point-to-point. Everything the brush and eraser do is clipped to it, antialiased edges included, so a diagonal is a diagonal rather than a staircase.

Hold Shift to add to a selection, Ctrl to take away, and both to keep only where the two overlap. A feather softens the edge by as many pixels as you ask for.

Three buttons sit just above the marquee: deselect, copy and cut. They stay on screen even when the selection is scrolled half out of view.

Transform picks a region up and lets you move, scale and turn it before putting it down:

Drag inside the box	Move it
Drag a corner or edge	Scale it; the opposite handle stays put
Shift while scaling a corner	Keep the proportions
Drag outside the box	Turn it
Enter	Put it down
Esc	Throw the move away

Nothing touches the layer until you put it down. Abandoning costs nothing, and undoing restores both where the pixels went and the hole they came from, in one step.

Copy, cut and paste work across tabs, and with the rest of the machine. A screenshot pastes straight in, and a region copied out of Umber can be pasted anywhere else. On Linux that lasts only while Umber is running, unless your desktop has a clipboard manager, which is how X11 and Wayland work rather than anything Umber decides.

Documents

Umber saves to OpenRaster (.ora), the same format it reads, so anything you make here opens in Krita, GIMP, MyPaint, Drawpile and Pinta. There is no format of its own, deliberately.

Opens
.ora	OpenRaster: Krita, MyPaint, GIMP, Drawpile, Pinta
.kra	Krita
.clip	Clip Studio Paint
.psd	Photoshop
.png	a flat image

Exports
PNG, JPEG, TIFF, GIF, BMP	flattened, with what each format will cost this document named before it writes

Anything lost on the way in is named in a notice when the document opens, rather than buried in a log: a flattened group, a dropped mask, a blend mode with no counterpart. Formats that would import subtly wrong are refused by name instead.

The installed packages offer Umber for all five, so you can open one from your file manager. Umber is added as a choice rather than taking the file type over, so whatever opens your .psd files today still does.

On Windows and Linux the packages also draw thumbnails, so a folder of .clip or .kra files shows the artwork instead of a row of identical page icons. macOS does not have this yet.

Several documents are open at once in tabs, each with its own layers, history and view. A saved document carries its undo history, so one reopened tomorrow can still be stepped back through.

The workspace

Every panel is a module you drag where you want it, the tool rail included, and they are locked while you paint. Window → Customise layout unlocks them, and your arrangement is saved between runs.

Six themes ship. Two are Umber's own; the other four take their greys from Photoshop, Clip Studio Paint, Krita and MediBang Paint, so a painter arriving from one of those starts with colours they already know. Make your own from a copy of any of them. There is an interface scale for a dense display, which leaves the canvas alone.

Shortcut labels follow your own keyboard, so a Nordic layout shows the key that actually zooms. Settings → Input & pen is the page to open when a pen feels wrong.

Your work is hard to lose

• Autosave every five minutes, waiting for a gap between strokes so it never interrupts one and never pauses the canvas.
• Documents you have saved are written back. Ones you have not go to a folder of Umber's own, and those copies expire after a month, adjustable or off. Nothing Umber deletes is ever a file you chose the place for.
• Closing with unsaved work asks first, and names every document at risk.
• If Umber stops without closing properly, the next start offers its copies back, naming each document and when it was last written. Opening one puts the painting in front of you and writes nothing over the file it came from until you save it there yourself. Saying no keeps every copy where it is.
• If Umber does stop, a window opens saying so, and saying whether your work was written down and where. The technical details fold out, and go to a file you can attach to a bug report. Nothing is sent anywhere.

Controls

Input	Action
Left drag	Use the selected tool
B / E / S / T / I / H / Z	Brush / eraser / select / transform / eyedropper / pan / zoom
Ctrl + D	Deselect
Ctrl + C / X / V	Copy / cut / paste
Shift / Ctrl / both + drag with Select	Add to the selection / take away / keep the overlap
Enter / Esc while selecting	Close / abandon the outline
Enter / Esc while transforming	Put the picture down / throw the move away
X	Swap foreground and background colours
Alt + drag, or the eyedropper	Take the colour under the pointer. Drag off the window to take one from anywhere on the screen
Alt + move, nothing held	Resize the brush; right and up is bigger
[ / ]	Decrease / increase brush size
Middle drag, or Space + drag	Pan
Wheel / Shift + wheel	Scroll up and down / side to side
Ctrl + wheel	Zoom at cursor
Ctrl + + / - / 0 / 1	Zoom in / out / fit / 100%
Ctrl + Z, Ctrl + Shift + Z	Undo / redo
Ctrl + Shift + H / V	Flip the canvas left-to-right / top-to-bottom
Ctrl + S, Ctrl + Shift + S	Save / save as…
Two-finger drag (touch)	Pan and pinch-zoom

Everything except the held modifiers is rebindable. On macOS Ctrl here is Cmd, and the dialog names it that way.

Pen pressure works on touch screens and on Windows, where a pen arrives through Windows Ink carrying 1024 levels. Pens on macOS and Linux do not reach Umber through the window system yet. There it falls back to a flat setting or a speed-derived approximation, and a mouse always paints at full pressure.

What is not there yet

• Nine of the sixteen tools, shapes among them.
• Vector and adjustment layers arrive as a note, not as pixels. A Clip Studio vector layer holds strokes rather than a picture, and Umber has no vector renderer; rasterise it before saving and it comes across. Adjustment layers change what is below them, which Umber cannot do yet. Both are named when the document opens.
• Picking a colour from outside the window is Windows only. Inside the window the eyedropper works everywhere. On macOS and Linux the tool options strip says so, rather than the drag quietly doing nothing. There is no magnifier under the cursor yet, so a one-pixel target takes a steady hand.
• Three things about text, each of which the panel tells you about rather than letting you find out later. Lines break where you break them and nothing wraps. A line mixing left-to-right and right-to-left writing is shaped but not reordered. A character the chosen face has no glyph for is left blank rather than borrowed from another font.
• File thumbnails and "Open with" are Windows and Linux only. On macOS Umber does not appear in either, because both need Umber to ship as a proper .app bundle and it does not yet. docs/thumbnails.md has what that would take.
• Two commands still throw the undo history away: clearing a layer, and resizing the canvas. Both say so before you do them. Everything else is undoable, including deleting a layer.
• Transforming a linked set. Link groups move together through the stack. Moving several layers at once on the canvas is a larger change.
• A folder's own opacity and blend mode. Folders hold layers, and their eye and lock reach inside, but a group opacity needs group compositing. docs/layer-folders.md has the design and its cost.
• A navigator.

Building from source

cargo run --release

You need Rust 1.92 or newer. docs/architecture.md has the platform prerequisites, how the stroke pipeline works and why it is built that way. CLAUDE.md has every invariant that has to hold.

Licence

GPL-3.0-or-later. Umber is free software: you may use, study, share and modify it, and anything you distribute that builds on it must be free in the same way. See LICENSE.

The shipped brushes carry their own licences, CC0 and CC-BY, and their authors' names travel with them. docs/brush-sources.md records every one.

Archivo, the typeface, is bundled under the SIL Open Font License.

Lucide, the icon set, is used under the ISC licence, Copyright (c) Lucide Icons and Contributors.