I'm currently working on creating a personalized map of a friend's journey on the Pacific Crest Trail; the area being covered is the Western U.S. from Mexico to Canada. I'd like to design the map to be printed at a large format; somewhere around 18" x 27". This will be the first time I've created a map at a poster size, previously my work has been fairly limited to smaller formats in publishing. Some questions that immediately come to mind given that the map will likely be read at a distance of a few feet vs. up close are:
- what typographic point size range should I use for labeling? (ie is 7pt too small to start with?)
- what resolution and DEM sampling should I use for creating a shaded relief? (The map scale is ~1:2,800,000 using a LCC projection. Natural Earth's 1:10m hypso tints looks too pixelated at the mentioned size)
- how large should symbols be so that they can be read accurately but not look obtrusive?
- is there anything else I should keep in mind when working on a large format map design?
I ask these questions in advance as I foresee printing proofs at this size being rather costly, thus I'd like to have a good starting point beforehand. Any suggestions or links to online resources would be very much appreciated.