Element Size

[the bane]

New here, as the post count will probably suggest, but I have taken an interest in doing my own cartography for a Role Playing Setting I am building. I had been using a free online resource to make my maps, but after finding some awesome Tuts here, I have decided to give it a try myself.

Background: Computer Engineer by trade, older in years, prefer Linux at home (so looking at using GIMP, but a novice user), have had some art training (years ago)... blah blah.

Anyway, the question. Did I mention I have ADD and OCD? The question, right... I want to make some base elements/brushes and wondering what size I should go with so that they scale well and look good big or little? Also, not sure how to change the dpi either. What dpi, once I figure it out, should I start with?

Thanks before hand,
The Bane

[Midgardsormr]

Dpi depends on how the map will eventually be viewed. The standard for high quality printed maps is 300 dpi. That assumes the viewer will be looking at the image at less than arm's length. For a poster-sized printed map, 150 dpi might be enough, although it depends on the size of the details.

If the map will never be printed, dpi doesn't matter at all. In that case, only the actual pixel dimensions matter, and they should be based, again, on how you want the map to be viewed. If you want the entire thing to fit on an average screen so that the viewer doesn't have to scroll, you should shoot for maximum dimensions of 1024 x 768. That's really quite small, though, and if you're shooting for that size, I'd suggest you actually design it at least twice as big and scale down right before exporting your final image (don't forget to undo back to full size before saving your master document, though!)

The resolution of individual elements is going to depend on what size you ultimately choose to work at. Size the elements appropriate for the image you are making. Some people like to design their brushes and stamps at twice their working resolution so that they can increase the size of the canvas they use later on and not have to redesign their brushes. The only hard and fast rule is don't scale up. You'll almost always lose quality if you increase the size of a raster image. So it's almost always best to design things at a larger size than you'll need because you don't lose much quality when you scale down.

[the bane]

Midgardsormr ~ thanks, it is appreciated. I suppose I will take a look at a 1024x768 image and kinda base my elements on what I think would ever be the largest I would want them for that space. I noticed that most of the 'templates' for GIMP default to 300dpi, but I am not sure what dpi a non-template defaults to, or how to change/check it.

Guess there is nothing to it but to do it!

Best,
The Bane

[Midgardsormr]

I'm sure a Gimp user will be along eventually to show you where the image size controls are.

Again, if you're not printing, dpi is irrelevant. You can set your dpi to 20 or 20000, and it won't make a bit of difference to how it appears on the screen or the file size. Further, it can be changed after the fact if you decide you do want to print. If, for instance, you decided you wanted to print your 1024 x 768 image to an 8 x 10 format (8.5 x 11", minus reasonable margins), you can just do a little bit of math to get it to come out to the right size. The long dimension is 10" and 1024 pixels, so that makes it 102 pixels (dots) per inch. The short dimension is 768px / 8" = 96 dpi. So somewhere in the range of 100 dpi would make your 1024 x 768 image letter-sized.

If you need a 24" x 36" image at 150 dpi (a decent poster print, but nothing you'd hang in a gallery): 24 X 150 = 3600px by 36 X 150 = 5400px.

It should also be mentioned that the paper makes as much difference as the print density.

[geamon]

It's best to have the X and Y resolution the same if your gonna print so it doesn't stretch the image. If you are having issues maneuvering around GIMP, http://www.gimp.org/tutorials/, can answer most if not all your questions.

[Fransie]

Go vector, no need to worry about dpi then

[the bane]

geamon ~ Thanks! Doah... I had used that all the time, but for some reason my is in Inches I believe... never made the connection.

Fransle ~ I have dabbled with Inkscape and love how allows for flawless scaling. Just wouldn't want to do a whole map in it. Guess I could look at opening the image at whatever scale I wanted it into Gimp?

Best and thanks all, again.
The Bane