This tutorial is going to give an overview of blending modes in photoshop. Blending modes give you ability to drastically change the way layers interact with each other. Most designers cycle through blending modes using trial and error to determine the correct one to use, but it helps to know a little about what each blending mode does:

Normal

As you can tell from the name, this is the standard state of the layer and there is no interaction between the current layer and the layer behind it.

Dissolve

This mode removes a random selection of pixels from the current layer which results in a jagged or fuzzy effect.

Darken

The darken mode compares the pixels of the current layer and the layer behind it and displays the darker pixels which usually results in a darker image.

Multiply

This is one of the most useful modes. It works by multiplying the colour of the lower layer with the colour on the top layer, resulting in a darker image.

Colour burn

This mode darkens the lower layer of the image giving you a dark effect.

Linear burn

This mode darkens the base layer to create an effect which blends in well with the top layer. This is one of the most complex of the blend modes.

Lighten

This does the opposite to the darken mode, displaying the lighter pixels.

Screen

This mode does the same calculations as the multiply but uses the inverse values to display the final image. This mode normally leaves you with a lighter image.

Colour dodge

This mode lightens the base layer compared to the top layer and leaves you with a lighter image.

Linear dodge

This is another complex blending mode. It makes the base layer lighter to make it fit in with the current layer more naturally.

Overlay

This is also a very popular and useful blending mode. It mixes the colours of the base layer and top layer but maintains the highlights of the layers.

Soft light

This mode determines whether the colours of the base layer are closer to black or white and either lightens or darkens the colours accordingly.

Hard light

This is very similar to the soft light mode but produces more dramatic results.

Vivid light

This mode either burns or dodges the colours in the image depending on which colours are present.

Linear light

Similar to vivid light but uses brightness to alter the colours in the image as opposed to the contrast used by vivid light.

Pin light

This mode creates varied results and works by replacing colours in an image depending on the lightness or darkness of the colours in the current layer.

Difference

The colours in the base layer and the current layer are compared and the difference mode subtracts one from the other based on which one is brighter.

Exclusion

This gives similar results to the difference mode but is usually more subtle.

Hue, saturation, colour and luminosity

These modes are all quite similar and work by mixing the hue, saturation and brightness from the base layer and the current layer.

So there you have it, a basic run down of how blending modes work. I hope you found it interesting and useful.