Plastic skin has one cause: colour and texture were corrected together. Separating them is the core of the technique, and it is less complicated than it sounds.
Retouched skin looks plastic when colour and texture are corrected together, usually by blurring or smoothing. Keep them apart instead: frequency separation lets you even out tone on one layer while pores stay intact on another, dodge and burn restores the shape that evening the tone flattens, and lowering the opacity of the finished retouch to around 70–85% returns some of what was removed. If pores are no longer visible at 100%, the retouch has gone too far.
Every plastic-looking portrait has the same cause: someone tried to fix uneven colour with a tool that also removes texture.
Skin has two independent problems. Colour: redness, blotches, shadows under the eyes, uneven tone across the forehead. Texture: pores, fine lines, the surface structure that makes skin look like skin.
Blur, smooth or clone across an area and you fix the colour by destroying the texture. That is the whole failure, and everything below is a way of avoiding it.
Frequency separation in plain terms
The technique splits one image into two layers:
- A low-frequency layer holding only broad colour and tone: a soft, blurred version of the face.
- A high-frequency layer holding only fine detail: pores and lines, with no colour information.
Stacked with the right blend mode, they reproduce the original exactly. The difference is that you can now work on colour without touching texture, and on texture without touching colour.
Even out a blotch on the low layer and the pores are unaffected, because they are not on that layer. Remove a spot on the high layer and the colour around it stays as it was.
Step by step
1. Remove the obvious things first, on their own layer.
Use the healing brush on a new empty layer set to sample all layers. Spots, stray hairs, dust, lint on a collar: anything that is clearly temporary rather than part of the person.
Doing this before the split keeps obvious flaws out of both frequency layers.
2. Split the frequencies.
Make two copies of the layer. Blur the lower copy with a Gaussian blur until the pores just disappear. The right radius depends on resolution and on the face, so judge by eye rather than copying a number. Use apply image on the upper copy against the lower one, with the settings for your bit depth, and set it to Linear Light.
Group the two layers. Everything below happens inside that group.
3. Even the colour on the low layer.
Lasso an uneven area with a generous feather, then blur it lightly or work over it with the mixer brush at low opacity. Aim for slightly more even, not flat. Work at 100% but check at 33% often, because every face looks blotchy at 100% and it is easy to over-correct.
Redness around the nose, shadows under the eyes, blotchy cheeks, uneven forehead tone: all of it is dealt with on this layer.
4. Clean texture on the high layer.
Clone stamp at 100% opacity, sampling nearby skin with similar texture. Because this layer carries no colour, you can sample from a slightly different part of the face without creating a tonal mismatch.
Remove specific things rather than working over whole areas.
5. Rebuild the shape with dodge and burn.
This is the step that separates "cleaned up" from "retouched", and the one most often skipped. Evening colour flattens the face, so the shape has to be put back.
Add a curves adjustment layer set brighter with a black mask, and another set darker with a black mask. Paint on them with a soft brush at a very low flow, around 2 to 5%.
Burn the sides of the nose, under the cheekbones, under the jaw, the crease of the eyelid and the outer edges of the forehead. Dodge the bridge of the nose, the tops of the cheekbones, the centre of the forehead, the chin and under the eyes.
Follow the light that was actually there. You are strengthening it, not inventing a new one.
6. Pull the whole retouch back.
Put everything in a group and lower the group's opacity; somewhere between 70% and 85% is common. This single move is what makes retouching read as natural, because it returns a fraction of everything you removed.
Rules that keep skin looking real
Keep the pores. If you cannot see skin texture at 100%, you have gone too far.
Keep the person. Freckles, moles, scars, laugh lines and skin markings belong to the subject. Whether any of them is removed is the client's decision, so ask before touching them.
Do not slim, reshape or enlarge anything unless asked. Liquify on a face is a request, never a default.
Check at three sizes. 100% for texture, 50% for tone and a thumbnail for overall impression. A retouch that only works at one size is not finished.
Look again later. Skin is the thing retouchers most often overwork when tired, and a fresh look is where that shows.
What "natural" means to a client
It means they look like themselves on a good day. Not younger, not smoother, not different. The client should be unable to say what was done, only that they like the photograph.
Beauty Retouching, at $5 per image, is built on the same two methods, frequency separation and dodge and burn, and it does not deliver completely smooth skin: distractions come out and texture stays. To judge the difference at full size rather than read about it, the portfolio shows before-and-after pairs.
Adjusting the method for different faces and outputs
Deeper skin tones. Watch colour as well as brightness when dodging. A lightening curve can pull deep skin towards grey; if it does, correct the colour on the low-frequency layer instead of raising saturation across the face.
Mature skin. Lines are structure, not blemishes. Reduce the depth of a line by lightening its shadow slightly rather than cloning it away, and the face keeps its age while looking rested.
Stubble and beards. Stubble lives on the high-frequency layer. Remove individual stray hairs there, and avoid blurring the low-frequency layer across the beard line, which leaves a smudged edge.
Print and screen. A large print shows skin close to life size, which makes both leftover blemishes and over-smoothing more visible than on a phone. Check at the size the client will actually see.
Common questions
Do I still need frequency separation if my software has a skin-smoothing slider? For anything viewed closely, yes. A smoothing slider evens colour and texture together, which is exactly what causes plastic skin; frequency separation lets you treat them separately.
Should I remove freckles, moles and scars? Not unless the client asks. They are part of the person, and removing them is a decision about someone's face that belongs to that person.
What blur radius should I use for frequency separation? Whatever makes the pores just disappear on your file. It depends on resolution and on the face, so judge by eye rather than copying a number from a tutorial about a different image.
Why does the face look flat even though the skin is clean? Evening the tone removed the modelling and it was not rebuilt. Dodge and burn is what puts the shape back; it is not an optional finish.
Can I retouch skin on a JPEG? You can, but a 16-bit file made from the raw gives better results. An 8-bit JPEG shows banding sooner in smooth areas once you dodge, burn and stack adjustments.
Related reading: 10 Retouching Mistakes Clients Notice Immediately and How to Whiten Teeth Naturally in Portrait Retouching.
BeEdits Editorial Team
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