“Gun-stock” carving. Lines per inch define sizing aspect if the tools. If you have a set that covers one Size as in 6 lines per inch, you would also need a set for 8 and ir 10 pines per inch. Those are Rte three basic sizes. Whether they cut on forward stroke or back stroke of the tool.makes a huge difference as well. I have purchased single line tools, forward and backward if 6 and 8 inch varieties a most common. Some 3 or 4 lines per inch, but most are two, one to align with previous and one to carve next In width in one tool. Typically yo can find if searched for, up to 4 individual cutters wide with to one alignment tool. Use 5 lines width
::] one to follow original line with 4 additional cutting edges, in forward or backward directions and there are reasons for both.