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Hi Joshua,

>>>>Anyone else having this issue?
Yes.

There is a bug in Preview app (in macOS High Sierra and later releases) which resulted in black areas on hard copy, when you print PDF files created in AutoCAD with solid hatches with transparency.

When AutoCAD creates PDF with its build-in PDF "printers" from drawing with such solid fills, it creates raster image with transparency areas. Such areas are invisible in PDF, but they exist and Preview app prints them as black areas.

Workaround is to print using Adobe Reader or other application which doesn't use macOS PDF engine. Or convert PDF to raster image before printing.