The em-square is the drawing area every glyph lives in. The horizontal lines are the font metrics: baseline (where letters sit), x-height, cap height, ascender and descender. The left vertical is the glyph origin (x = 0); the amber vertical on the right is the advance width — how far the pen moves before the next letter.

Tools: P pen, N node, H pan. F fits the view.

Pen: click to drop corner points; click-drag to drop a smooth point and pull its handles. Click the first point to close the outline, or press Enter to close it. Esc cancels the outline in progress. A glyph can have several outlines — draw the outer shape, then draw a second outline inside it for a counter (the hole in O, A, e).

Node: drag anchors to move them (handles follow); drag handles to reshape — hold Alt to break the two handles apart. Double-click an anchor to switch it between corner and smooth; double-click a segment to insert a point; Delete removes the selected anchor.

Advance & metrics: drag the amber advance line, or set it as a number on the right. Font metrics (units-per-em, ascender, cap height, x-height, descender) are shared by every glyph and editable on the right.

Accents & marks: the set includes four diacritic marks — ´ acute, ˇ caron, ˚ ring, and the caron used on lowercase ď/ť — at the end of the character grid. Draw those four plus the plain base letters (a, e, c, …), then hit Compose accents: every Czech accented letter is built as a composite (base + mark stacked, shown in blue) with the mark auto-positioned above the base. Composites can't be drawn on directly — nudge the mark with Mark X/Y, or Decompose to turn one into editable outlines. Editing a base or mark updates every letter that uses it.

Glyph: the character box on the right chooses which glyph you're drawing; ‹ › step through printable characters. Each glyph is stored separately, so you can rough out several letters.

View & history: zoom with the −/+ buttons or Ctrl+scroll, Fit with F, pan with the Hand tool, space-drag, or the middle mouse button. Ctrl+Z / Ctrl+Shift+Z undo/redo. Everything autosaves to this browser.

Export & preview: Export .ttf builds a real TrueType font and downloads it — install it in your OS and type with it anywhere. WOFF builds the same font as a compressed web font (.woff) for @font-face on a site. Preview loads the built font into the strip below without downloading. Specimen PNG/SVG export a shareable sheet showing the whole set, a Czech pangram, and a size ladder (the SVG is self-contained with the font embedded). Only glyphs you've actually drawn (plus .notdef and space) go into the font; undrawn letters simply aren't mapped.

Save & load: Save writes the whole project to a .json; Load reopens one. Opening a project file is treated as untrusted input and validated before anything is drawn — nothing from the file is ever run.