Whilst it is easy to enlarge or reduce graphic objects, font sizes either become too large or are unreadable because they are too small. It is best to get it right from the start (i.e. tailor make the map).
Web-designers can easily change the size of a map, but it is most inadvisable for them to do so because there is a massive drop-off in clarity.
It is best for the cartographer to generate the map to fit a specific space rather than trying to fit the map to the space available after it has been created (applies to JPG, GIF and PNG files). Trust me on this one!!! – maps do not behave like other graphics.
There is a slight colour drop off in generating PDF files, but the map is able to be enlarged with no loss in clarity (i.e. you don’t get the pixel-effect). This is great for the viewer, especially if there is a lot of small detail.
Maps that you see embedded on your monitor (JPG, GIF, PNG files) will usually be much smaller when printed. Fine detailed maps, whilst visible on the monitor may be unusable when printed. Maps are therefore generated in several sizes/resolutions and/or file formats to suit the end usage.
This PNG file map example is for the location of Taupō Primary School. This is an example of a raster image. If you zoom into the image you will see pixels appearing and the image will become fuzzy. While it looks ok on your screen, when printed it will not be as good.