The Glue Filter

Use Glue when a drawn detail should remain a separate, editable part while joining a larger outline. A serif can keep its own source contour, attach to a stem, and update when you edit either the stem or the serif.

Gluing an Open Contour to a Body

The Glue filter connects the endpoints of an open contour to a closed body. The element containing that open contour becomes the glued element. FontLab puts the participating content in a glue construction, shown in the Elements panel, and calculates the joins from those inputs.

Prepare an open detail whose endpoints face the body at the intended attachment. A disconnected shape far from the body does not tell Glue where a useful join should go. Keep the body closed and position the detail so that its endpoint connection can meet the body.

Apply Glue

  1. Put the closed body and open detail in the same glyph layer. They can begin in separate elements.
  2. Select the open contour with the Contour tool, or select its element.
  3. Choose Element > Glue Selection.
  4. Select the resulting glue construction in the Elements panel and inspect both joins.

You can add further open details to a body by positioning and gluing them in turn. Inspect the nested elements to distinguish the construction from the source detail you want to edit.

With the construction active, its controls let you adjust the connection. To edit the source instead, select the body or glued element inside the construction in the Elements panel. The distinction is useful when an attempted contour edit appears to select the whole result.

Control the joins

Each open contour has two green glue connection points, one at each endpoint. Click a connection point to switch between a smooth join and a sharp join. A smooth join follows the adjoining direction; a sharp join retains a corner.

Judge each end separately. A serif may need a smooth bracket at one end and a deliberate sharp transition at the other. Inspect the result in a filled view as well as with contours visible.

The central glue positioning point controls how the detail follows movement of the body. Clicking cycles through four behaviors: stay in place, follow horizontally, follow vertically, and follow in both axes. Use horizontal following when the detail should move with a stem's sideways repositioning but retain its vertical placement; use both axes when it should travel with the body.

Move the body a small amount after choosing a follow state and check the response, then undo the test move. This confirms the behavior without relying only on the point's small visual indicator.

Resolve the result

The construction remains adjustable until you expand it. Element > Expand Filters converts the calculated joins and detail into editable outline geometry. Element > Remove Filter removes the Glue construction and exposes its source elements.

Inspect the structure after expansion. Use Ungroup, Flatten, or further contour operations only when the remaining structure and your next edit require them. Keep a saved version with the live construction if you want to continue adjusting the attachment later.

Pinned Attachment and Reuse

Pins give Glue named attachment locations. Put a pin named p1 on the body and a pin named _p1 in the glued element. The underscore marks the attaching pin, and Glue aligns it with the matching body location. A named body node can also supply a matching position.

A second pair, such as p2 and _p2, establishes an attachment direction as well as a position. Glue can rotate the detail and scale it along the line between the pins to fit the two pairs. If their distances differ, do not expect a rigid rotation that preserves every dimension of the detail.

If several body locations have the same name, Glue chooses the geometrically nearest match for an attaching pin. Place the detail close to its intended attachment before relying on that choice. Use distinct names when repeated locations would make the nearest match ambiguous.

Make a reusable serif

  1. On a saved copy of a glyph, isolate the nodes and segments that form the serif. Move the detail into a separate element with Contour > Convert > To New Element.
  2. Inspect the stem left behind. Repair the gap and close its contour, retaining the corner or edge to which the serif should attach.
  3. Keep the serif contour open at its two attachment endpoints. Position it against the repaired stem.
  4. Add matching pins if the attachment should follow named positions rather than its current placement alone.
  5. Select the serif and choose Element > Glue Selection.
  6. Adjust the connection points and following behavior, then check the filled result.

To use the same drawing elsewhere, insert or paste an element reference to the serif source into the other glyph. Position it, provide matching attachment pins where needed, and glue it to that glyph's body. Edit the shared serif source to update the referencing constructions.

Glue and reference sharing are separate choices. Applying Glue does not turn independently drawn serifs into references, and a normal copy operation is not a substitute for deliberately creating a reference. Confirm the shared relationship before expecting a font-wide edit to propagate.

If one serif must diverge, unlink that element reference before editing its source contour. You can keep the local Glue construction live while giving it an independent drawing. Expanding the entire construction is only necessary when you want to edit the generated outline directly.

Older files may contain a legacy glued group with a different engine and controls. The current workflow uses connection-point clicks and the central positioning point; older tutorials describing separate Glue context-menu options do not describe those current controls.