Roselith Color Plates

Turn an image into four color plates. Roselith is an offline workbench for mathematical CMYK separation and round-dot halftone studies. All current tools are included in one upfront purchase. No subscription, account, advertising or in-app purchases. FOUR POSITIVES Import a PNG or JPEG and view cyan, magenta, yellow and black together. Adjust each ink’s screen angle, density and tone gamma. Study the digital composite with individual ink visibility and common black share. Visibility changes the composite only; all four positives still export. Undo and redo retain 20 settings changes. Keep eight named ink/output presets. REAL PRINT FILES Save each print independently with eight files: a five-page A4 or US Letter PDF, four opaque black-positive PNGs, a composite PNG, settings CSV and editable Roselith JSON. PDF plates share corner registration targets and a 100 mm reference line. PNGs contain physical resolution metadata. Settings CSV includes measured raster coverage and exact pixel/physical dimensions. Preview PDF pages and positive PNGs in the app. Save individual files through Android Documents or share through the system chooser. REOPEN AND RESTORE Saved prints remain separate from later project edits and deletion. Reopen an earlier print or restore its embedded working image and settings as a separate editable project. Import a Roselith JSON backup to continue editing. Search, rename, duplicate or explicitly delete projects. Your selected project survives relaunch. Production starts empty; City terraces, Orchard dusk and Color steps are optional original studies. CHOOSE THE OUTPUT 40–160 mm requested width, 150 or 300 DPI, 12–50 lines per inch. Actual dimensions are reduced as needed to fit 180×220 mm and 2000 pixels per axis. Print at 100%, disable fit-to-page and measure the reference. High frequency at low DPI has few pixels per dot; choose 300 DPI or a lower frequency. LOCAL LIMITS PNG/JPEG up to 8 MiB and 24 megapixels. Android converts the source to a white-backed sRGB working PNG up to 1600 pixels per axis; project JSON retains this normalized editable source and settings. JSON import up to 16 MiB. Keep 24 projects within 64 MiB, eight presets and 24 independent saved prints within 512 MiB. Full libraries refuse a new save without silently deleting earlier work. Back up outside the app before deleting or uninstalling; there is no trash or cloud sync. Android system backup is disabled. SCOPE Standard RGB mathematical CMYK and round-dot digital studies. Not ICC separation, a calibrated color proof, press-certified output or a guaranteed print result. No spot-ink matching, underbase, exposure/mesh calculation or moiré avoidance guarantee. Verify your printing with your materials and process. Use images you own or may use. No app Internet, camera, microphone or broad storage permission. Your chosen file provider and sharing destination follow their own policies.

First Android release: offline CMYK halftone plates, per-ink controls, digital composite studies, independent eight-file prints, aligned PDF and DPI-tagged PNG export, local presets and editable project backups.