Open-Top Paper Box Net Builder

How to use Open-Top Paper Box Net Builder

Enter ideal inside length, width and height in millimeters. Choose optional glue tabs, a paper format, margins and panel labels. The tool constructs five rectangular faces and optional chamfered tabs, classifies cuts and folds, checks the unscaled paper footprint and exports a real SVG with exact flat and assembled coordinates.

1. Use the example as the schema; replace its labels and entered model assumptions.
2. Enter ideal inside length, width and height in millimeters. Choose optional glue tabs, a paper format, margins and panel labels. The tool constructs five rectangular faces and optional chamfered tabs, classifies cuts and folds, checks the unscaled paper footprint and exports a real SVG with exact flat and assembled coordinates.
3. Calculate, inspect the complete report and limitations, then copy the report or download the generated JSON or SVG artifact.

Good to know

• Length and width are 10–500 mm; height is 10–200 mm. Margin is 5–25 mm. All measurements are exact decimal strings with up to six places. With tabs enabled, glueTabMm is 1–100 mm, no greater than height, and twice its value cannot exceed the interior width. Without tabs it must be exactly 0.
• Choose A4 or Letter in portrait or landscape, or custom. Each sheet reserves two 12 mm annotation bands plus the entered margins measured to net centerlines. The 0.2 mm round strokes extend 0.1 mm into those margins. A preset that cannot contain the original-size net is refused; no rotation, scale-to-fit or multi-sheet tiling is applied. Custom sheets are at most 950 × 974 mm. Five faces, up to four tabs, 28 net segments and a 50,000-character SVG cap.
• Zero-thickness, open-top paper model only. Four tabs attach to the north/south wall sides and fold onto west/east wall interiors; opposing tabs may touch at boundaries. The static assembled witness verifies hinges and face geometry, not a dynamic folding path, material thickness, bend allowance, adhesive strength or packaging suitability.
• SVG coordinates round once to 0.000000001 mm; exact report fractions preserve the model. Title uses at most 80 UTF-16 code units and is escaped. Text keeps its normal glyph proportions with conservative per-code-unit font reduction for bounded slots; it is never stretched to fill a line. Very small sheets or glue tabs can still produce tiny type; omit panel labels when unreadable and inspect actual font fallback. Print at 100% and verify the 20 mm line. Native rendering, fonts, printer calibration and cutting/folding safety require checking.
• Local calculation with no upload, input persistence or outside lookup. Model JSON is limited to 30,000 characters and 10,000 values. Decimal quantities are strings with up to six places; count fields use plain JSON integers. Exact fractions are capped at 8,192 bits. The complete JSON output is limited to 1,000,000 characters; approximate numbers preserve their stored values. Unsupported states fail explicitly.