The remaining color mismatches at layer edges can be corrected using
layer masks. The idea is to blend the edges by using a gradient in a
layer mask. The technique of layer blending using a gradient in a
layer mask is discussed in Section
Construction of a Gradient in a Layer Mask to Blend
Away the Boundary Between Two Layers
shows the remaining color mismatch at the edge between layers A and B.
(b) shows a layer mask created
for layer A. This mask is a black to white gradient where the black
point is placed at the left edge of the mask and the white point
slightly to the right of this. This layer mask has the effect of
making the left side of layer A's boundary semi-transparent, letting
layer B show through. The end result is the two layers are blended in
this small band removing the visibility of the boundary.
(c) illustrates the Layers
dialog showing that four of the five layers have had layer masks
added. This makes one layer mask for each boundary.
The Result of Blending Two Layers
shows, again, the boundary between layers A and B before blending.
(b) shows the result after
blending. As you can see, the technique is very effective. However,
some experimentation was necessary to find the correct width for the
Although the gradient blending trick works well in most cases, there
are times when it is not appropriate for the entire boundary between
two layers. In this case, parts of the boundary can be targeted for a
blending gradient by using the Rectangle Select tool. This is necessary, for example, for the blend of layers
D and E. Here, separate selections are made at layer D's left edge
for the regions corresponding to the hardwood floor, the wainscoting,
and upper wall areas. Separate gradient blends are produced for each
The layer mask produced by these separate gradients is shown in
Using the Rectangle Select Tool to Create a Custom
(b) shows the associated Layers