[Award Winner] Drawing hand drawn maps in Gimp

[torstan]

The second way to do this is as follows.

Follow the same process as before so that you have a pasted layer with a white background above your parchment layer. However don't set the layer mode to multiply.

Before going further, use the layers dialogue to correct the whites as described above. Now we are ready to move on.

With the scanned image selected go to Layer->Transparency->Color to alpha...

Make sure that the box beside "From:" is white. This will turn all instances of white on this layer into a transparent image. Now you see why we needed to have the background as pure white as we could. Press okay and you will see your white background magically disappear. I prefer this to the multiply method because you aren't affecting any other layers with this. Multiply does affect the layers below it so it can create some wierd glitches further down the line. Plus it will be useful to be able to mess with the line layer modes later on which we can't do if we are relying on them being set to multiply at this stage.

This should give you an image much as before:



Now this is a little light so we'd like to make it a bit darker. With the scanned layer selected press ctrl-shift-D or go to Layer->Duplicate Layer. This should darken the lines nicely. Play with the opacity of the new layer (using the opacity slider in the Layers Dialogue) until you decide it is dark enough. Then right click on the duplicated layer and go to Merge Layer Down. This gives you a lines layer as before. This now looks something like this:

[ravells]

Thanks Torstan, this is really useful stuff. I hadn't appreciated the downside to using the multiply approach to the alpha approach. I think I'll stick to the alpha approach from now on.

[torstan]

Multiply is also really useful if you want to use a reference drawing. So for example say you found a map on google of a region you wanted to turn into a hand drawn map. Copy that image to your computer. Open up your parchment image as above. Open up the Google image and scale it so it will fit nicely over your parchment layer. Create a new layer over your parchment layer and paste the Google image on to it:



This gives you something like this. Now change the Layer mode to multiply and you get something like this:



Now create a new transparent layer (remember shift-click), choose the ink tool and start tracing round the coastline, along roads and so on until you have a line drawing of the map you are after. This way you need never complain of lack of hand-drawing skills or inspiration again!

Now that we have got our ink lines by subterfuge, deceit or elbow grease, we'll move on to colouring the image tomorrow.

[torstan]

Okay, now that we have our lines, we need to get some colour down. In this case there are four different coloured areas - the sea, the deck, the sails and the rocks. First things first - create four new transparent layers and name them for the colours they will hold.

We'll start with the sea colours. We could just do a block fill of a nice sea colour to start with, but that's a bit dull. It's more interesting if we can get a bit of variation in the colour for the sea, so we will build it up bit by bit.

For varying colours I find it useful to use the airbrush with the 'Use colour from gradient' switch turned on. Gimp comes with a deep-sea gradient so that seemed particularly appropriate for this case but you can use others, or make your own. In this case I use the following settings:



Now take a large fuzzy brush and block in the sea with colour. Note that I have scaled up the brush to aid in quickly filling a large area. Don't worry if it's not smooth at this stage. We'll deal with that in a minute. Also, don't worry if the colours aren't quite right. They are just going to give us a starting point. Finally, the edges are also not a great problem. It is more important to get the colour up to the edges of the area you are filling in than worry about going over into the adjoining area.

The end result will look blotchy and non-too smooth. Switch from the airbrush tool to the smudge tool. Now I decided that I wanted it to look as if the waves were rolling in from the north-east. Therefore I use the smudge tool to blur the colours in lines from north-west to south-east. Here is a screenshot of the smoothing in progress. Note that the area in the bottom right of the image has not been smoothed yet.



Notice how the colour variation smooths out to give the impression of waves. Now this still looks a bit lurid. I'll deal with that next.

[RobA]

---Useful tangent---
Note that shift-clicking the new layer button in the layers dialogue creates a new layer with the last used values. This saves ages when creating lots of new layers like we will be doing here.
---end of tangent

I'd rep you for that if I could... never knew that one! Thanks

-Rob A>

[torstan]

Very glad to be of use. Sounds like you need to spread the love around a bit. Find some maps to rep and come back!

Okay, a bit more after a holiday sailing on the Mazurian Lakes. Yes, I like boats in RL too.

After using the smudge tool over the bluey green sea colours I ended up with this result:



Now this is pretty lurid and not at all a reasonable sea colour, let alone a nice wash colour over a parchment background. To get that we only need to change the layer mode from normal to overlay and, viola, we get a great faded wash over the sea area.



However this is clearly not there yet. This gives us a dappled blue and green base, but we need a darker blue background for the sea.

[torstan]

-------- Another small tangent ---------

A few handy viewing tips in Gimp to help with getting a decent view of your image.

• ctrl-shift-e maximises the image to fit within the window you have open, such as in the second image above.
• 1 - pressing 1 will get you to 100% zoom.
• F11 - toggles full-screen. You can then use ctrl-shift-e or 1 to see your image at a large scale within full-screen.

-------- end of tangent -------

Now we want to get a nice dark blue for the sea to give it a deep-sea look. For this map I used the City Colours palette provided by Rob over in his Mapping a Region in Gimp tutorial. I used the dark blue with the airbrush tool and a large fuzzy brush (remember to uncheck use-colour-from-gradient) to block in the dark blue sea. Again, don't worry too much about edges, we'll deal with them soon enough. After blocking in the colour, use the smudge tool to smooth out any obvious edges and get a relatively smooth finish. Here's a screenshot with the colour laid down and the other sea-colour layer turned off:



Now, we have no interest in having block colour on the map. The idea is to let the variation of the paper texture beneath show through to give texture to the whole image. No surprises then that we want to switch the layer type to overlay again. With the other sea colour layer turned off (note there is no eye icon beside the other sea colour layer on the left) this looks like:



With both overlay layer's switched on we get:



This is starting to look like a dark storm tossed sea,but we could still do with going darker. We could duplicate the dark blue overlay layer to darken it further, but in this case I decided to go with a burn layer instead.

I duplicated the dark-blue overlay layer and switched the layer mode to burn. This makes everything very dark so I reduced the opacity to 20%. This gives the result:



This is pretty close to what I want for my sea colours now.

So the basic method for colouring in these maps takes the form:

1. Block in the colour with a large fuzzy brush. If you want some colour variation use a good gradient of colours and check Use-colour-from-gradient.
2. Use the smudge tool to smooth out the obvious edges.
3. Set the layer to overlay
4. Experiment with duplicating the layer and using other layer modes for the second layer - possibly burn for a dark, moody edge, or normal with low opacity to bring up the colours.

Next I'll make good my promise of dealing with the edges that I coloured over.

[torstan]

Okay, after a bit of an extended break here's the next step. Currently the coloured layer for the sea bleeds over - a lot - into the areas that we don't want to be sea coloured. The plan is to clean up those edges. There are a few ways to do this. Firstly there is the obvious choice - take the eraser tool and go round the edges - yes it's that easy.

However, we have a number of sea colour layers, and it's going to take a while to go over all the edges for each one. Not only that, but we may well erase something we actually wanted to keep. The best way to deal with this is using layer masks.

1. Open a new layer (shift-click the new layer buttin to open a new transparent layer as before).
2. Take a hard edged black brush.
3. Turn off the pressure sensitivity to opacity if you are using a tablet.
4. Colour black all areas that aren't going to be covered by the sea colours.
5. Name the layer Mask.

You should now have an image that looks something like this:



Don't worry that you are drawing heavy black lines over your beautiful creation, they won't be there for long. This step takes a little time, but it will save time in the long run.

1. Make the Mask layer invisible so that you don't see the large black image messing up your image.
2. Go to one of your sea colour layers, right-click -> Add layer mask. Accept the default setting of white (full opacity).
3. Go back to your black Mask layer.
4. Select all (ctrl-A) and copy (ctrl-C).
5. Select the white layer mask you created at step 1 by going to the layers dialogue and clicking on the white box that is beside the thumbnail of your colour layer.
6. Paste (ctrl-V) the black image of your non-sea area. As the layer mask (rather than the image) was selected, you won't drop a large black blob over your map. Instead the black lands on the layer mask. Click the anchor button at the bottom of the layers dialogue to anchor the pasted layer to the layer mask.

You should now have nice sharp edges on your colour layer rather than the spread of colour over the lines. You can repeat the process for all the other colour layers you used to give yourself a nice sharp edge throughout.

Now the layer mask is useful for the sea, but it is also useful for the other areas. Go to a new area - say the deck colours that currently is empty.

1. Right click the layer -> Add layer mask... and keep the white(full opacity) setting as before
2. Paste the Mask image on to this layer as before.
3. With the layer mask still selected go to Colour->Invert

Now the layer mask is the mirror image of the sea colour mask. This means that any colours you lay down for the deck will run up to precisely the edge of the sea colours and no further. This saves a lot of eraser work later.

This should give you something like the following: