Portolan Chart vs Stamen Map Styles (Toner, Terrain, Watercolor)
ポルトラーノ海図 / スタメンの地図様式
Portolan Chart comes from Diagrammatic Expression and Stamen Map Styles (Toner, Terrain, Watercolor) from Information Design. They are reached for with some of the same intent, which is where they get confused.
Portolan Chart
A medieval working sea chart, crossed by radiating rhumb lines. Coastlines and place names run precisely along the vellum while flags and monsters fill the empty water, from a time when a map's usefulness and its ornament had not yet parted.
Stamen Map Styles (Toner, Terrain, Watercolor)
Stamen Design published three named basemap styles: Toner in high contrast black and white, Terrain built from hill shading and vegetation colour, and Watercolor made of washes with soft edges over paper texture. What changed with them is that the look of a basemap became a style you pick, not a set of colour settings you adjust. Cooper Hewitt acquired Watercolor, which was launched in 2012 and released under a Creative Commons Attribution licence.
| Portolan Chart | Stamen Map Styles (Toner, Terrain, Watercolor) | |
|---|---|---|
| Era | 13th–17th century | 2010s– |
| Family | Diagrammatic Expression | Information Design |
| Kind | Style | Style |
| Cues | Radiating rhumb lines / Names perpendicular to coasts / The vellum ground / Flags and monsters as ornament | Toner is drawn in black and white with no grey midtones at all / In Watercolor the shore reads as the soft edge of a brush stroke, and the paper texture stays visible as you zoom / Watercolor renders water as blues mixed with turquoise and violet, and roads swing from orange to red brown / Labels, lines and ground are separate layers, so a tile set ships with any of them left off |
| Best used for | Books and exhibitions telling the story of routes or trade as a map · Ornamental maps whose real subject is the memory held in place names | When the basemap has to drop to black and white so strong colour can be layered on top of it · When a location map on an invitation or a guide should read as a painting on paper rather than a data panel |
| Type | Names packed perpendicular to the coast, key ports raised in red | Keep labels out of the basemap and add them back as a separate layer only when needed. Use one typeface and change its size by one step per zoom level. |
| Composition | Several compass roses with straight lines radiating across the sheet | Hold the same map as three layers: ground, lines, labels. Drop layers as the data on top gets denser, so the map itself carries less. |
| Material | Black and red on a vellum ground, flags and monsters in open water | Draw Toner as two values with no midtone. For Watercolor, scan washes painted on real paper and map them onto tiles through a scripted process, keeping the soft edges and the grain. |
| Caution | Drawing rhumb lines as pattern while ignoring how they answer the roses gives ornament that no longer looks like an instrument of navigation. | Lay thin lines and small type over Watercolor and they lose to the soft edges and the paper grain, so nothing stays readable. |