# ISOLINES System Variable [GstarCAD 2021](Help%20System/GSTARCAD/2021/Index.md) → [System Variables](Help%20System/GSTARCAD/2021/System%20Variables/(System%20Variables).md) → [I](Help%20System/GSTARCAD/2021/System%20Variables/I/(I).md) **Function Description:** The ISOLINES system variable is used to specify the number of contour lines displayed on the curved surfaces of 3D solids. | | | | --- | --- | | Type | Integer | | Saved in | Drawing | | Initial value | 4 | | Range | 0 \~ 2047 | --- ## Other versions with matching text [GstarCAD 2016](../../../2016/System%20Variables/I/ISOLINES%20System%20Variable--f5df8da81546.md) · [GstarCAD 2017](Help%20System/GSTARCAD/2017/System%20Variables/I/ISOLINES%20System%20Variable--f5df8da81546.md) · [GstarCAD 2018](../../../2018/System%20Variables/I/ISOLINES%20System%20Variable--f5df8da81546.md) · [GstarCAD 2019](Help%20System/GSTARCAD/2019/System%20Variables/I/ISOLINES%20System%20Variable--f5df8da81546.md) · [GstarCAD 2020](../../../2020/System%20Variables/I/ISOLINES%20System%20Variable--f5df8da81546.md) · [GstarCAD 2022](Help%20System/GSTARCAD/2022/System%20Variables/I/ISOLINES%20System%20Variable--f5df8da81546.md)