Where to find an accurate Mercator Projection world image?
So here is the way I do that personnally with NaturalEarth data and R (but you can do something similar i m assuming with any programming language that can deal with GIS or any GIS software):

Fist download and unzip the file:



download.file("http://www.naturalearthdata.com/http//www.naturalearthdata.com/download/10m/physical/ne_10m_coastline.zip", "10m_coast.zip")
unzip("10m_coast.zip")


Then reads in the shapefile:

library(rgdal)
library(maptools)
a &lt;- readShapeSpatial("ne_10m_coastline.shp",CRS("+proj=latlon +ellps=GRS80"))


Then project it:

a_merc &lt;- spTransform(a,CRS("+proj=merc +ellps=GRS80"))


And plot it:

pdf(w=20,h=20,file="merc.pdf")
par(mar=c(0,0,0,0))
plot(a_merc,asp=1,xaxs="i",yaxs="i")
dev.off()


This is a very minimalist example of course, it only draws the coastlines (as a line by opposition to drawing the continents as polygons, that would allow a more advanced colouring scheme but the projection to mercator of polygons is more complex, as Antarctica creates problems).