PLT to SK Converter

Convert HPGL plotter drawings to Sketch SK vector format

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Open-Source Path

Move PLT plotter data into SK format — opening the door to free, open-source vector editing with Skencil on Linux.

Quick Delivery

Cloud processing converts your PLT to SK in seconds, even for drawings with complex HPGL path structures.

Secure Processing

PLT uploads are deleted immediately after conversion. SK downloads are purged from Convertio within 24 hours.

How to convert PLT to SK

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose sk or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your sk file right afterwards

About formats

PLT is a vector file format associated with HP-GL (Hewlett-Packard Graphics Language), a plotter control language introduced by Hewlett-Packard in 1977 with the HP-9872 pen plotter. PLT files contain a sequence of two-letter ASCII commands that instruct a pen plotter to move, draw lines, select pens, and render text — commands like PU (pen up), PD (pen down), PA (plot absolute), and SP (select pen) form a straightforward instruction set that directly controls physical drawing motion. The language operates on a coordinate grid measured in plotter units (typically 0.025 mm per unit), and the resulting files read almost like machine code for a drawing device. HP-GL became the dominant standard for computer-aided design output, adopted by virtually every CAD application and supported by plotters from all manufacturers throughout the 1980s and 1990s. One advantage is universal CAD compatibility — PLT files generated by AutoCAD, SolidWorks, or any engineering software can be sent directly to plotters and cutting machines without driver translation. The text-based, human-readable command structure is another strength: engineers can inspect, edit, and hand-write PLT files to troubleshoot output or generate simple drawings programmatically. HP-GL/2, an enhanced version introduced with the HP LaserJet III in 1990, added polygon fills, Bezier curves, and raster support. PLT remains actively used in engineering, architecture, and manufacturing for large-format output.
Developer: Hewlett-Packard
Initial release: 1977
SK is the native file format of Skencil (originally named Sketch), a free vector graphics editor for Linux created by Bernhard Herzog, with the first public release on October 31, 1998. Skencil holds historical significance as one of the earliest full-featured vector drawing applications written almost entirely in Python, with only performance-critical rendering components implemented in C. The SK file format uses a text-based, Python-like syntax to describe document structure — pages, layers, groups, and individual graphic objects are represented as nested statements with parameters specifying coordinates, colors, line styles, and transformations. The format supports Bezier curves, rectangles, ellipses, text objects with font specifications, imported raster images, gradient and pattern fills, and hierarchical grouping with affine transforms. One advantage is human readability — SK files can be opened in any text editor, making it possible to inspect, modify, or generate artwork programmatically using simple scripts. The Python-native structure also provides a benefit for automation: since Skencil itself is a Python application, the file format integrates naturally with scripting workflows for batch processing and procedural graphic generation. While Skencil's development slowed after the mid-2000s, its SK format became the foundation for the sK1) project, which extended the format and continued active open-source vector graphics development. SK files remain convertible through sK1, UniConvertor, and other open-source tools.
Developer: Bernhard Herzog
Initial release: October 31, 1998

Frequently Asked Questions

Why convert PLT to SK?

SK is the native format for Skencil, a free vector editor — converting PLT lets you edit plotter drawings in open-source design tools.

What programs handle SK files?

Skencil (formerly Sketch) is the primary application. UniConvertor can also read and convert SK files to other formats.

Is the vector structure preserved?

Yes — HPGL vector paths are mapped to SK geometry, keeping the structural accuracy of the original plotter drawing.

Is SK format still actively used?

While niche, SK remains relevant in open-source vector editing workflows, particularly on Linux systems.

Is PLT to SK conversion free?

Yes — Convertio provides free PLT to SK conversion. No downloads, no registration, no fees.

Can I convert from a phone?

Certainly. The converter runs in any mobile browser — upload your PLT file and receive an SK result on the go.

PLT to SK Quality Rating

5.0 (2 votes)
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