Greyboard (also known as chipboard, binder board, or bookbinder board) is a dense, rigid board manufactured from 100% recycled unbleached paper pulp. It forms the structural skeleton of rigid setup boxes.
### Understanding Caliper Measurement Units:
Packaging board thickness is measured in three common units depending on region and material:
| Unit | Full Name | Common Use | Conversion Equivalent |
|---|---|---|---|
| mm | Millimeters | Rigid greyboard & corrugated | $1.5\text{mm} = 1500\,\mu\text{m}$ |
| Microns ($\mu\text{m}$) | 1/1000th mm | UK/EU folding carton board | $400\,\mu\text{m} = 0.4\text{mm}$ |
| Points (pt) | 1/1000th inch | US paperboard specifications | $16\text{pt} \approx 400\,\mu\text{m}$ |
| GSM ($\text{g/m}^2$) | Grams per sq. meter | Paper weight / density | Board density varies by type |
### Typical Greyboard Thickness for Rigid Boxes:
- 1.2mm–1.5mm (800–1000gsm): Small luxury jewellery & watch gift boxes.
- 2.0mm–2.5mm (1300–1600gsm): Standard luxury perfume, electronics, and liquor presentation boxes.
- 3.0mm+ (2000gsm+): Extra-heavy luxury hampers and display cases.