Re: [Gimp-user] Adding color to file

[Guy Stalnaker <jimmyg521 gmail com>]

I'd like to suggest an alternative method for coloring an image that has
some great advantages.

Use layers with masks!

   1. Open PDF in GIMP
   2. Scale image to increase dpi to 300 (for printing): menu Image > Scale
   Image > set X and Y resolution to 300
   3. Crop if needed
   4. No need to duplicate base layer because you're going to leave it alone
   5. Add new layer
      1. Fill with a color you want for some part of your image
      2. Give layer name (e.g., face, jacket, etc.)
      3. Set the Mode to Soft light, or some other appropriate Mode (in the
      example Soft Light lets the background show through)
      4. Add mask to the same new layer: Right-click > Add Layer Mask
      5. In dialog for Initialize Layer Mask to: select Black (full
      transparency), click Add
      6. On the Layer click on the new Mask box to select it (a white
   rectangle should appear around it)
   7. Because the mask was added at Full Transparency, the color of the
   layer should NOT be visible
   8. Use the Brush Tool to "paint" where you want the color to show --
   Select the Brush tool and set its size, I vary this based on need, but a
   good starting point is brush "2. Hardness 025", at size 15
   9. Select from the Color Selection the color White; if you have the
   default which is Black foreground and White background, click on the swap
   control to reverse them. If no White, click on the foreground color box
   then from the resulting dialog select White
   10. Now, with your mouse (layer is active and mask is selected) use the
   brush to "paint" on the image, which you can see because the mask is set to
   transparency, where you want the color of the the layer to show. You should
   see the color appear.
   11. Add new layers for new colors as needed
   12. Save as .xcf to retain all of this layer information for later use
   13. Export to .png for other people to use. You may find setting the
   background outside the bounds of the image to transparent helpful for other
   uses if the image will be "placed" onto a document page, etc.

There are great advantage of this technique:

   1. You can easily change the color of any layer
   2. You can change the layer mode
   3. You can change the layer opacity
   4. You can edit the mask by swapping to black and "painting" which
   "removes" the color by reversing the transparency
   5. You never have to create a selection area, or edit a selection after
   the fact (horrors!)
   6. You never mess with the base image nor do you need to duplicate
   it--you just add color layers, as many as needed, and use the brush where
   you want the color to be visible

A proof-of-concept image is attached as a .xcf so you can see the layers
used, etc. -- a black and white image of a cowboy that's been colorized
using this technique (which I did not devise myself--it was found via
Google search, but long ago, and of such value that I've long since added
it to my standard repertoire of GIMP techniques that I frequently use).

Hope this is as helpful for you, if you have not used this technique
before, as it was, and has been, to me.

Regards,

Guy S.

Guy Stalnaker
jimmyg521 gmail com

On Thu, Oct 5, 2017 at 2:02 PM, sl60 <forums gimpusers com> wrote:

> I want to color parts of what has been sent to me as a black-and-white pdf
> (line
> drawing, basically). What I usually do in a case like this is to change the
> original layer to Multiply, then duplicate this and multiply again. Then I
> select each part of the drawing I want to color and bucket fill it
> (different
> colors for each). if I save this as a pdf and open it, all it shows is the
> colors without the line drawing. if I save it as a png, all is preserved.
>
> My question is--should I save the pdf as a png or jpeg first before I
> start the
> entire process? It's a very low resolution drawing. Or does it matter?
> It's a
> big file (the original is on a 24"x36" sheet and it will probably be
> printed out
> at some point).
>
> I thank you for your help in advance!
>
> --
> sl60 (via www.gimpusers.com/forums)
> _______________________________________________
> gimp-user-list mailing list
> List address:    gimp-user-list gnome org
> List membership: https://mail.gnome.org/mailman/listinfo/gimp-user-list
> List archives:   https://mail.gnome.org/archives/gimp-user-list