Toning Black and White Photographs in Gimp


When I did black and white printing in my old traditional darkroom using paper and chemicals I used to love the effects I got from using chemical toners on my prints. Toning a black and white print enhanced depth giving deep rich blacks and greater overall contrast. There were several colours of toner available - sepia, blue, copper etc and each of them gave the print a warm or a cool look and the amount of toning could easily be controlled by the length of time you soaked the print in the toning solution


I then discovered that you could use two tones - one for the highlights and one for the shadows. This process is called Duotoning and it carries on into the digital age because there are Gimp and Photoshop techniques for doing just that


Here are some notes on a Gimp Duotoning technique for black and white images which I found in an excellent video by Rolf Steinort and Philippe Demartin which I downloaded from the Meet the Gimp website. The link to the video is at the bottom of the page


Summary

Create a new layer and fill it with the colour you want for toning the highlights

Create a new layer and fill it with the colour you want for toning the shadows

Sharpen the image


Before and after Comparison

Here is my first attempt at using the technique:


Image before toning

Before Toning


Image after toning

After Toning


Open an Image

Open a black and white image. This image is our Background Layer


Toning the Highlights

1. Create a new layer and fill it with the colour you want for toning the highlights (a warm orange)

2. Name this layer 'highlight' and set it's layer blending mode to 'Color'

3. Select the background layer and select all (ctrl+a) and copy the image to the clipboard (ctrl+c)

4. Create a layer mask on the 'highlight' layer, select the mask and then ctrl+v to paste in the image

5. The image now looks orange and we have a new floated selection in the layers palette

6. Anchor the floating selection


Toning the Shadows

1. Create a new layer above the highlight layer and fill it with the colour for the shadows (a cool blue)

2. Name this layer 'shadow' and set it's layer blending mode to 'Color'


Repeat steps 3-6 above on the shadow layer


7. Select the layer mask on the shadow layer and convert it to a negative - Colours > Invert

8. Change the opacity of the highlight and the shadow layers to around 20%


Sharpening

1. Duplicate the background layer and move it to the top of the layer stack

2. Name this layer 'sharpen' and set the layer blending mode to 'Value'

3. From the menus go : Filter > Enhance > Unsharp Mask

4. Radius and Amount will depend on the size of the image so experiment until it looks right

5. Reduce the Opacity of the sharpen layer to suit


Links

Meet the Gimp Dutoning Video Tutorial