What is an island?
An island is paper that touches no edge of the canvas. A frame holds each layer by its edges, so a piece that reaches no edge has nothing to hold it once the cut is made. It may look correct on screen, but after the surrounding shapes are cut away, the piece will fall out or lose its intended position and angle.
Common examples include:
- The center of a letter such as A, B, D, O, P or R.
- An eye, window or small interior detail surrounded by a cut.
- A branch, highlight or facial feature isolated from the rest of its layer.
- A shape created when two nearby cut-outs meet.
KerfPress marks detected islands so you can decide how each piece should be held or assembled.
What is a bridge?
A bridge is a narrow strip of uncut paper that connects an island to paper that reaches an edge, or to the edge itself. It keeps the piece in its correct position during cutting, lifting, alignment and assembly.
A bridge is part of the structural layer, not a separate object to cut and glue. Depending on the design, you can leave it in the finished project, hide it behind another layer or trim it after the island has been supported and glued in place.
How KerfPress handles islands during generation
When KerfPress builds a layered SVG, it checks whether each paper layer remains connected.
Where possible, the generator may use an additional same-color depth layer to support an island. It also attempts to add bridges to pieces that still need a paper connection. The result summary reports how many bridges were added and warns you if any islands remain unresolved.
Automatic processing is a practical starting point, not a substitute for checking the finished design. Open the SVG editor when a bridge needs a different position, an island remains unresolved or a loose piece would work better as a decal.
Add bridges automatically in the editor
The editor provides two ways to add bridges automatically.
Add bridges to the current layer
Select the layer you want to repair, open Islands & bridges in the left panel and choose Auto-add bridges. KerfPress connects each island on that layer to the nearest paper that reaches an edge, or to the edge itself.
Use this when you want to inspect and refine one layer at a time.
Connect all detected islands
When islands exist anywhere in the project, the editor displays a warning above the layer list. Choose Connect all to add bridges across every layer that currently contains detected islands.
To do it in one step with a file on your computer, drop it on Add bridges to an SVG automatically. The editor opens and connects every island for you.
Afterward, inspect the result at the finished size. An automatically chosen bridge may be structurally valid but visually distracting, so you may still want to move it, replace it with a manual bridge or use a decal instead.
Add a bridge manually
Choose Add bridge manually, then select the two endpoints on the canvas. Place one end on the island and the other on connected paper.
Manual placement is useful when:
- The shortest bridge crosses an important visual detail.
- Another layer can hide the bridge more effectively.
- The bridge should follow an existing edge or feature.
- You want more control over where the island remains attached.
Make sure both ends overlap paper. A bridge that does not reach both pieces cannot create a physical connection.
Freestanding cut-outs
Freestanding cut-outs, like a single figure or a card insert, have no frame. Turn off Detect islands in the left panel and the editor stops marking islands. Bridges you already added stay editable.
Check disconnected bridges
Editing a shape can move the paper away from a bridge that previously worked. KerfPress marks a bridge as Disconnected when it no longer connects the intended pieces.
Use Auto-add bridges again to repair the affected layer, or delete the disconnected bridge and place a new one manually. Always recheck islands after moving, resizing or deleting shapes.
Choose a practical bridge width
Bridge width is a real physical measurement based on the finished size of the project.
A bridge that is too narrow may tear while cutting, lifting the sheet from the mat or assembling the project. A bridge that is too wide is stronger, but may become visible or change the appearance of the design.
Start with the global bridge width, then inspect every connection at the intended cutting size. Individual bridges can use their own width when one location needs more or less support than the rest of the project.
The minimum paper width in the generator also sets the initial bridge width for generated layers.
When to use a decal instead
Not every island needs a bridge. A decal is a separate piece that is cut independently and glued onto the surface of a structural layer.
Use a decal when:
- Every possible bridge would be clearly visible.
- The piece is small and easy to position from the placement guide.
- The detail belongs on the surface rather than inside a cut-out.
- A bridge would distort the silhouette or an important edge.
Use a bridge when the piece must keep its exact position and angle during cutting and assembly. Use a decal when a clean disconnected shape matters more than keeping it attached to the sheet.
Preview bridges without changing the file
KerfPress offers bridge display options so you can inspect the design more easily:
- Keep bridges shows them as part of the paper.
- Mark bridges highlights their locations.
- Hide bridges removes them from the preview.
These options change only what you see on screen. Hiding bridges in the preview does not remove them from the exported cutting files.
Keep or remove bridges from the download
Downloads keep bridges by default. This is the safer option because the connected pieces retain their position while the layer is cut and assembled.
Choose Remove bridges from download only when you deliberately want the exported geometry recalculated without them. Once removed, an island becomes a loose piece and may shift, rotate or fall away during cutting.
When a download contains bridges, KerfPress includes a bridge location guide to help you find them during assembly. The guide is a visual reference, not a cutting file.
Cut and assemble bridged layers
Keep each bridge intact while removing the layer from the cutting mat and positioning it in the stack.
- Place the structural layer in its final position.
- Add a spacer beneath the island at the correct height.
- Glue and support the island.
- Let the adhesive hold the piece securely.
- Trim the bridge carefully.
Do not cut the bridge before the island is supported. Without the connection, the piece can lose its position and angle.
Final island check
- Every warning has been reviewed.
- Each island is connected by a bridge or intentionally made into a decal.
- No bridge is marked as disconnected.
- Bridge widths suit the finished project size and material.
- Important details are not blocked by unnecessary bridges.
- You know which bridges will remain and which will be trimmed.
- Removing bridges from the download is intentional.