World Map Specs

[Almajis]

Hello, Guild!

I'm trying to make my first world map. I'll be using only my own resources, my wacom intuos 4 and GIMP. I will also be printing this map in a 120x90 cm (48x36 inches) sheet of paper. However, I do have a few questions about this project:

1. How many ppi should I use? I usually go for 600 ppi.
2. Should I make the initial image 48x36 or is that too big? I mean, the canvas alone exceeds 5 GB.
3. Is there any template I could use here in the Forums?

Thanks in advance. I'll be posting my WIP as I go, in order to receive your valuable feedback.

[jbgibson]

The 600dpi goal might totally kill you, if you don't have scads of memory & a hefty cpu/gpu. There's ways to get around that - work a few layers at a time in separate files, and merge them as you go into a master output file. 300 dpi might suffice for decent printed output. Once you give away bits you can't get them back - it would be sensible to work at as high a resolution as you think you want, and downsize later if you must. Or you could make a mere set of outlines at 600dpi, then do your mapping continent by continent in separate files, combining only when you need to apply some effect or operation across all at once.

[Deadshade]

It depends on your computer. But like jbgibson I think 600 ppi is Deadly for most systems - it certainly is for mine and I have a decent CPU and graphic card.

[Zenka]

I did my map on 60x60 cm at 600dpi (later printed on 80x80). It was just managable with 8GB of ram if I gave photoshop access to all of it. (dunno how GIMP does this. I hope there is an option for it)
If you have 16GB of ram you could go for 600dpi. (given you have a decent cpu)

In the end, you are going to print it at 300dpi anyway. So you could just go for a slightly bigger canvas to allow for some cropping and 300dpi.

Separating the layers or sections to different files is a way to stay with a high dpi as well.
A high dpi is nice if you later on decide to print it even bigger. Going for 450dpi will give you some headroom as well.

[Chick]

You need a minimum of 300 dpi to print. Less than that and you will be able to see the pixels. Professional digital artists suggest working at double this, and when the image is completely done, shrink it to 300, so your plan to work at 600 ppi is excellent and right in line with the professionals.

As the others have said, this does require a pretty good computer with plenty of memory and power. If you have that, definitely stick to the 600. For my professional mapping here, I work even higher than that to get excellent clarity.

If that turns out to strain your computer too much, then work at 600 in a smaller 24 x 18 inches, rather than reduce the resolution. When you double the size for final printing, you will still have the required 300 resolution.

[johnvanvliet]

i work on maps that can exceed 12 to 24 Gig
images that are 65536 x 32768 and 131072 x 65536 pixels

but not all at one time . i crop out tiles .


most printers are good at 300 dpi

to NOT burn your self out on something TOO big

start with say a image that is 7200x3600 or 20 pixels per degree for a full planet
-- that is 150 dpi for a 48 inch paper ( 14400 x 7200 pixels is 300 dpi for a 48 in. paper)
------- 90 North -------
-180 W to-0-to +180 E
------- 90 South ------

but as above
for GOOD printing
print at 600 dpi and make the image BIGGER that that

and for a 48 x 36 ( well 24 in with a border) in poster that is a rather BIG image


for working on WHOLE large images i use the image software
"Nip2 "
it is the GUI to the imaging library VIPS
it is SPECIFICALLY !!!! designed to work with imaging data sets that can exceed 100Gig to 1 Terabit
-- and it is GPL'ed
http://www.vips.ecs.soton.ac.uk/index.php?title=VIPS

i use nip to cut out a tile
and work on that tile in gimp

[Almajis]

THANK YOU ALL for those great replies. I will try 600ppi and then shrinking the image for printing at 300ppi. I don't know how my computer will react - I have a dcecent computer (regarding memory and graphics card), so I'm hoping GIMP will behave. If I see there's some strain in my computer, I'll just do the whole thing in 300ppi. As Johnvanvliet said, I will try the 20 px per degree on my map.