Vellum Kettle

Vellum Kettle is an offline-first skin log for scribes, bookbinders and re-enactors who turn calf, goat and sheep skins into writing vellum. Replace scraps of paper and guesswork with a precise record of every skin, from the first soak to the final cut. THE HERSE FRAME The app opens on a fullscreen, top-down view of your stretching frame holding the active skin, ringed by 16 to 24 tension pegs. Tap a peg to add a quarter turn, long-press to back off. Colour coding shows slack, even, tight or overdrawn tension, and the peg tension map is saved with the skin. SEVEN STAGES, ONE RIBBON A slim stage ribbon runs through Flay, Lime, Unhair, Stretch, Scrape, Pumice and Cut. Advancing a stage timestamps it and unlocks that stage's inputs. LIME BATH LOG Record bath number, slaked lime grams per litre, pH, water temperature, soak days and stirring events. A vertical strength gauge flags baths that look too weak or too harsh against a fresh, mid or spent scale. Bath reminders such as "Stir the kettle" or "Swap to the stronger bath on day 4" follow a per-skin schedule. SCRAPING AND DRYING Count lunellum scrapes and chalk dustings, add typed humidity and weather notes, and watch a drying-tension trend line build up over each session. PUMICE FINISH TRACKER Note the grit side (flesh or hair), number of passes, pounce and chalk used, then rate final thickness in tenths of a millimetre. A translucency meter fills as you record it. SKIN LIBRARY Browse a card grid of every skin with species (calf, goat, sheep, deer), size, side marks and current stage. Filter by species, stage or outcome: vellum, parchment or spoiled. RECIPE BOOK Start from six historic-style lime and soak recipes, such as Slow Calf, 10-day, or Quick Goat, 6-day. Apply one to a new skin and save your own variants. COMPARE TWO SKINS See bath strength curves, peg maps and finishing notes side by side with differences highlighted, so you can work out why one skin came out translucent and another cockled. SHARE YOUR BATCH Export a batch sheet as text or PDF to share with your workshop or guild. Everything works offline, so it is ready in the workshop wherever you are. Built for people who care about the craft and want to repeat their best skins.