Very Large Maps, is it a problem?

[jwbjerk]

...the only real working difference is that when you zoom to 100%, the larger the ppi the smaller it will appear on the screen.

I don't know about GIMP, but in photoshop zooming to 100% means that every pixel on your screen represent a pixel in your document. I.E. there's a one-to-one correspondence. DPI or PPI is irrelevant to how "100%" looks on screen.


Some other Tricks:

* I like to use "Solid Color" Adjustment layers when they make sense in my maps. They create only 1 channel worth of information instead of 4.
The "foundation" layer that contains the shape of my coastline is a "solid color" layer, and i clip mask everything i want to conform to the coastline to it. To create a solid, semitransparent layer of color, like to delineate a temperature zone, political boundary, or a biome, i'll generally use a solid color layer. I can just paint on the mask to change the size-- i don't have to worry about selecting that precise color again, or accidentally painting on it.


* Gradient maps are a great way to make topographic effect that adjust themselves as you edit the map. They are also gentle on the file-size. See step #11 of my mini tutorial.


* In photoshop (and i think GIMP) you can set the bit depth of each channel. Going from 8 bits/channel to 16 or 32 greatly increases the file size and processing time. For map-making you will not regret leaving it at 8 bits/channel.


* You can never have too much RAM or scratch disc space for Photoshop. In Photoshop's preferences you can allow additional HardDrives to serve as a scratch disc. (the precise way you do this varies with the version). Adding fast drives, especially with lots of GBs free to the scratch disk list can greatly boost photoshop's performance on those time-consuming commands.