Convert PT3 to SFD

PostScript Type 3 (PT3) is a file format developed by Adobe Systems in the 1980s for font files in PostScript language. Unlike the more common PostScript Type 1 format, PT3 allows for the inclusion of complex graphics and color. However, it is less widely used due to its lack of support for hinting, which affects the clarity of text at small sizes. PT3 was largely replaced by Type 1 fonts and later OpenType formats. It served as an important step in the evolution of digital typography, allowing greater flexibility and creativity in font design.

The SFD (Spline Font Database) file extension is primarily used by FontForge, a font editing software. SFD files are ASCII-based, making them human-readable and easily transferable across the internet. They store comprehensive font data, including outlines, character data, and bitmap fonts. Introduced by FontForge, SFD files have evolved to support multiple layers and complex font features. This format facilitates detailed font design and editing, ensuring compatibility across various operating systems.