A fine cutting blade would work I suppose for longer straight sections. Also, If you check various websites for hand tools you will find a hand carving tool in various widths similar to the ones pictured below! I prefer to use this type of tool to create the effect you are picturing! it is slower but allows for variation in width and movement for a more natural effect. I purchased mine from Bonsai Tonight. The tool on the right is called a grafting chisel and is also useful for fine intricate cuts with some depth.looking for a dremel bit for making the fine lines... been looking for days and no luck.
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