# PREVIEWTYPE System Variable [GstarCAD 2025](Help%20System/GSTARCAD/2025/Index.md) → [System Variables](Help%20System/GSTARCAD/2025/System%20Variables/(System%20Variables).md) **Function Description:** The PREVIEWTYPE system variable is used to control which viewport will use the drawing thumbnail preview. | | | | --- | --- | | Type | Integer | | Saved in | Drawing | | Initial value | 0 | | Range | 0,1 | **System Variable Value:** **0:** use last saved view **1:** use the main view --- [Original help](https://www.gstarcad.net/help/GstarCAD_2025_en-US/detail/systemVariables/PREVIEWTYPE.html) · © Gstarsoft Co., Ltd.