Some fabric-reinforced duct tapes are designed to tear by hand. Ease and tear direction depend on backing construction.
Confirm product characteristics
Check whether the manufacturer specifies hand tearability. Trial a short piece at a suitable workstation and assess edge neatness and ease of use.
Choose for the workflow
For repeated tasks assess needed tape length and application time. If hand tearing is unsuitable, use an appropriate safe cutting tool and select tape for the application and surface.