A single mistake in the definition code—a misplaced comma, a rounding error, or a misaligned vector—results in the dreaded "Bad pattern definition" error in AutoCAD.

means batch processing. A professional tool should let you point to a folder of 50 DWG files (each containing a unique pattern) and output 50 PAT files in 30 seconds.

Don't let file format limitations dictate your design. Demand a converter that respects your geometry. Your patterns—and your deadline—will thank you. Do you have a specific DWG pattern you need to convert? Test any "better" converter with a complex geometry first. If it handles a 5-point star inside a circle, it can handle anything.

Furthermore, the converter should intelligently handle scale. You should never have to type "Scale factor 0.0034" into the Hatch dialog. The PAT file should store the pattern at 1:1 scale relative to the drawing units. If you draw in millimeters, the hatch works in millimeters. If you are an architecture firm or a material library manager, converting one pattern at a time is unacceptable.