Description
Compute a uniform inward rectangular canvas border area and fraction.
Studio measurements translate a design into lengths, areas, volumes, angles, proportions, and material quantities. Consistent units and an explicit geometric model make the calculation interpretable. Real materials, fabrication allowances, visual judgments, and installation conditions require information beyond a geometric term.
Compute a uniform inward rectangular canvas border area and fraction.
When to use this tool
Use Canvas Border Area Share when you need a geometric or material-budget term for a supplied studio design before checking real material and installation conditions.
How to use the tool and how it works
- Enter width, height, border. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read borderArea, borderShare. Use the output convention below.
Subtract the inner rectangle with dimensions width-2*border and height-2*border from the positive outer rectangle for borderArea, then divide by outer area for borderShare. Require border within half the smaller dimension.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| width | Width | Required. Finite number; strictly above 0. |
| height | Height | Required. Finite number; strictly above 0. |
| border | Border | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| borderArea | Border Area | Required. Finite number. |
| borderShare | Border Share | Required. Finite number. |
{
"input": {
"width": 10,
"height": 8,
"border": 1
},
"output": {
"borderArea": 32,
"borderShare": 0.4
}
}Limitations and assumptions
- The border is uniform on four sides and can consume the full interior. The tool does not choose an aesthetic border or account for irregular shapes or paint behavior.
- The field tables state structural bounds; the mechanics also specify cross-field constraints. Malformed inputs and unsupported domains cause errors. A successful false flag, empty branch value, or zero placeholder has the meaning stated above and is distinct from an input error.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Signed zero is exported as zero.
Alternative or Complementary methods
Use measured material allowances and a complete drawing or fabrication model when physical behavior matters. The supplied geometric term can be one input to that separate process.
References
Similar or alternative tools
- Lithographic Stone Image Border Area
Subtract imageWidth*imageHeight from stoneWidth*stoneHeight for borderArea and divide image area by stone area for imageFraction.
- Canvas Fold Corner Overlap Count
Separate the four square corners from the straight margin strips of a rectangular canvas expansion.