TITLE Par Avion — The Journey of One Letter PROMPT A scroll-driven story following a single airmail letter from a pillar box in an invented northern harbour town to a village on the other side of the world, in 1961. The envelope stays fixed at the centre of the viewport for the whole page; scrolling moves it through the postal system, and the envelope itself accumulates the evidence: postmarks, cancellation waves, transit stamps, a customs label, a redirect sticker, a crease, a rain blot, a salt-water stain, a thumbprint, a clerk's pencil. Concept: an object that is its own travelogue. Mood: tender, bureaucratic, wistful, quietly funny. Palette: kraft/manila sorting-office ground #D9C4A0, airmail blue #2A3D66, airmail red #C8102E, envelope paper cream #F7F1E3, graphite ink #3B3B3B (plus tints of these, and one violet ink for the desert transit mark). Light page. Texture: fibrous envelope paper, slightly uneven ink, the red-and-blue lozenge airmail border around the envelope edge, a fine paper grain over the scenes. The envelope (large SVG, centre stage, about 70% of viewport width on desktop and 90% on phones, gently rotating a degree or two as it "moves", and tilting very slightly in 3D toward the mouse): hand-addressed in a script-style italic stack ("Snell Roundhand", "Segoe Script", "Bradley Hand", "Brush Script MT", cursive) in blue-black ink: "Miss Ottilie Varga, The Schoolhouse, Kestrel Bay, via Port Halcyon, Southern Ocean Territory" (all invented); a "PAR AVION / BY AIR MAIL" etiquette label; two invented postage stamps drawn in SVG with perforated edges (one showing a lighthouse in blue engraving style, value 1/3; one a tern in flight in red, value 6d; issuing country invented: "NORDHAVN"); return address on the flap side ("T. Varga, 3 Net Loft Row, Skerrigate, Nordhavn"), where a violet Port Halcyon G.P.O. backstamp and a pencilled "1/9 pd." are also waiting to be found. Stages (each a scroll segment with a scene illustrated in flat duotone-ish SVG behind/around the envelope, as vignettes at the left and right edges on wide screens and as a window above the envelope on phones; scenes slide to the next with a horizontal conveyor motion; a caption block in the lower third; and marks added to the envelope): 1) The pillar box in Skerrigate, 5:45 p.m. collection: rain; the letter falls from above into frame and picks up a rain blot on the address. 2) The sorting office: a cancelling machine, a clock at 6.15: the first postmark: a circular date stamp "SKERRIGATE · 14 MAR 61 · 6.15 PM" with seven wavy lines across the stamps. 3) The night mail train: a travelling post office, pigeonholes, telegraph poles passing the window; the letter is flicked and gains a sorter's thumbprint. 4) The aerodrome (Halvard Field): sacks, a propeller airliner, a control tower; a blue oval "AIR TRANSIT" stamp. 5) A stopover on a desert airfield: a violet hexagonal transit mark "RAS EL-TAYYIB · TRANSIT" and a customs label slapped on. 6) The flying boat down the coast: a salt-water stain and a crease across one corner. 7) Port Halcyon G.P.O.: the address is found insufficient: a red pointing-hand stamp "NOT KNOWN AT THIS ADDRESS — TRY KESTREL BAY", then a clerk's pencilled note and underlining. 8) The weekly mail boat, then the postman's bicycle along the cliff road: a "REDIRECTED" sticker and a boxed "SHIP MAIL · M.V. PETREL" stamp. 9) Delivered: a final receiving postmark "KESTREL BAY · 2 APR 61", and the letter is opened. Signature moment: every postmark is physically stamped. At each stamping trigger, a handstamp (seen from above: a die plate in the shape of the mark, with a black knob) descends into view, strikes the envelope with a thump (a fast scale-down with a tiny envelope recoil and paper bounce), and lifts away, leaving the mark with uneven ink (SVG turbulence mask for patchy coverage, slightly doubled edge on one side, random small rotation), which then "dries" from wet-dark to matte over a second. Labels are slapped on, blots spread, the crease draws itself, the pencil note writes itself. Scrolling back up brings the handstamp back to lift each mark off in reverse (the letter un-travels). By the end the envelope is a dense, beautiful collage of thirteen marks, creases and labels; a counter in the corner tallies "19 days · 17,400 km · 9 pairs of hands". Finale: the envelope turns over (3D flip), a paper-knife slits the top fold, the flap opens to show a blue cross-hatched lining, and the letter slides out and unfolds in three panels: three paragraphs of handwritten-style text that the viewer has been carrying all along: a warm, specific, slightly comic letter from a brother to his sister about the harbour, a new kettle, their mother's knee and a ship's cat, ending with a line that lands gently. Then a small line: "She replied on the 4th. It took 23 days." and a "Post it again" button that un-travels the whole journey back to the start. Furniture: a route ribbon fixed at the top: a dotted great-circle-like line across a simplified invented map strip with nine place dots lighting up (each dot is a button that jumps to its stage), and a tiny envelope/train/aeroplane/boat/bicycle glyph that changes by stage; a date and local-time ticker that runs through each stage; a running tally; captions in a typewriter face (Courier/"American Typewriter") on small cream cards with a blue-red airmail edge, 30–50 words each, in the voice of a Post Office public-information film ("Seventeen people will handle your letter. None of them will read it. One of them will bend it."). Typography: titles in a 1960s public-service sans (Gill Sans/"Gill Sans MT"/"Trebuchet MS", bold caps tracked), script for handwriting, typewriter for captions. Opening screen: the title "PAR AVION" in airmail blue between rows of red and blue lozenges, each letter struck into place, subtitle "the journey of one letter", and a cue: a small stamp-shaped scroll indicator. A hidden detail: pressing and holding the envelope holds it up to the light and shows the folded letter inside. Optional sound toggle (off by default): handstamp thumps, rain, train rhythm, propeller drone, sea, gulls: all synthesised. Reduced motion: marks fade in without the handstamp animation; scenes cross-fade; the envelope cross-fades to its back instead of flipping. Responsive: scenes simplify on phones; the envelope remains the hero. DESCRIPTION A single airmail envelope sits at the centre of a kraft-paper stage and never leaves it. As the viewer scrolls, nine flat, duotone postal scenes conveyor past behind it — a rain-streaked pillar box, a cancelling machine, the pigeonholes of a night mail train, an aerodrome, a desert stopover, a flying boat, a colonial G.P.O. counter, a mail boat and a cliff-road bicycle, a schoolhouse — while a top ribbon traces the route on an invented map and a ticker runs the local date and time. The envelope is the travelogue: each stage physically strikes, sticks, stains or creases it, with handstamps that drop in, thump and lift away leaving patchy, slightly doubled ink that dries from wet to matte. Captions on airmail-edged cards speak in the dry voice of a public-information film. At the end the envelope turns over, a paper-knife opens it, and the letter it has been carrying the whole way unfolds: a brother writing to his sister about rain, a ship's cat, an honest kettle and their mother's knee. Scrolling back up un-stamps every mark and sends the letter home. VISUAL TECHNIQUES - Scroll-driven timeline with a smoothed progress value mapped to nine stages plus a multi-step finale - Large inline SVG envelope with fibrous paper made from anisotropic feTurbulence, a skewed-pattern lozenge airmail border, and two engraved-style stamps with masked perforations - Postmark ink filter: feDisplacementMap wobble, offset ghost edge, and two turbulence alpha masks for patchy coverage; random rotation per strike; wet-to-matte drying animation - Handstamps animated with the Web Animations API (accelerating descent, strike, lift) with a sprung recoil of the envelope - Label slap, blot spread, crease draw (stroke-dashoffset) and pencil write-on (clip-path) animations - Nine hand-drawn flat SVG scenes with looping details (rain, spinning cancelling wheel, passing telegraph poles, propellers, waves, smoke, windsock, ceiling fan), anchored left and right and re-framed for portrait screens - 3D envelope flip with two faces, a scaleY flap opening over a cross-hatched lining, and an animated paper-knife slit - Three-panel letter unfolding in CSS 3D with a growing drop shadow, ruled airmail paper and script type - Fixed route ribbon: non-scaling dotted arc on an invented map, progress stroke, lighting place dots and a stage-specific vehicle glyph - Running date/time ticker and eased numeric tally - CSS-masked perforated stamp as the scroll cue; lozenge rows from repeating gradients; struck-in title letters - Pointer-driven 3D tilt of the envelope and a hold-to-the-light reveal of the letter inside - Synthesised Web Audio: stamp thumps, rain, rail rhythm, propeller drone, sea, gulls INTERACTION MODEL Scrolling (wheel, touch, keyboard) is the journey: it slides the scenes past, moves the vehicle along the route ribbon, advances the clock and the tally, and at each trigger drops a handstamp, label, stain or crease onto the envelope; scrolling upward lifts them off again in reverse order. Past the ninth stage, continued scrolling flips the envelope, slits and opens it, draws out the letter, unfolds it and scrolls through it to the closing line. The stamp-shaped cue on the title starts the journey; the nine dots on the route ribbon are buttons that jump to each stage (marks strike in quick succession on the way); "Post it again" at the end returns to the start. Moving the mouse tilts the envelope slightly; pressing and holding the envelope holds it up to the light and shows the folded letter inside. The post-horn button in the ribbon turns the synthesised sound on and off (off by default). With reduced motion enabled, scenes cross-fade, marks simply fade in, and the envelope cross-fades to its reverse.