SK is a document format: it stores data in the SK format. PNG is a image format that uses lossless DEFLATE compression and supports a full alpha-transparency channel, preserving every pixel exactly as encoded. This renders each page as a raster image, making the content viewable without a document reader. Each page is rendered at the specified DPI and saved as a separate image; text in the output is no longer selectable. Converting between these two formats is common when the source application does not support PNG natively or when the target platform only accepts PNG. 1converter processes this conversion server-side using open-source tools. Files are transferred over HTTPS, converted on secure cloud servers, and automatically deleted after 24 hours.