3FR to SK1 Converter

SK1 is the native file format of the sK1 project, an open-source vector graphics editor and conversion engine started by Igor Novikov in 2003 as a successor to Bernhard Herzog's Skencil. The format evolved from the original SK format, extending its capabilities while maintaining the text-based, Python-readable syntax for describing vector documents. SK1 files encode complete document structures including multiple pages, layers, guidelines, and a full hierarchy of graphic objects — Bezier paths, rectangles, circles, polygons, text blocks, and embedded raster images — with attributes for fills (solid, gradient, pattern, hatching), strokes, and transformations. The sK1 project distinguished itself by focusing on prepress and professional print production features, adding CMYK color management, ICC color profiles, spot color support, and PDF/PostScript output — capabilities unusual in open-source vector editors. One advantage is professional color handling — sK1's CMYK workflows and color management make it one of the few open-source tools suitable for print-ready vector production. The project's companion tool, UniConvertor, leverages the SK1 format as an intermediate representation for converting between numerous vector formats (CDR, CMX, WMF, EMF, SVG, and others), giving SK1 significance beyond the editor itself as a universal interchange format. The text-based file structure preserves the readability and scriptability advantages inherited from Skencil's original SK format.