Preparing a 19th Century Printed Engraving for Halftone Printing Today. I “Descreened” in Photoshop. Thoughts?

Here’s an XCU detail of the original:
Gregor MacGregor from 1823 book

And here’s my finished version:
MacGregor image "descreened" in Photoshop

Using guidance at link below:

Descreening in Photoshop

Answer

My thoughts . . .

I wouldn’t try to create a halftone to reproduce it. It’s a beatiful engraving, so I think better to treat it as though it were line art, so that when printed it isn’t converted to a screened image at all.

I found this helpful blog post which describes the basic technique: Line Art – the One and Only True Bitmap format. As it stands, it doesn’t really work well with your example image because it’s not really high enough resolution, but I think you could tweak it a bit to get a decent enough result.

  1. Convert to greyscale

  2. Rescale the image by doubling its pixel dimensions. If the scan was 300ppi, this will effectively bring it up to 600ppi which should help keep pixelization to a minimum, or larger if you’d prefer. Alternatively if possible, rescanning it at a higher resolution would be the best.

  3. Convert to a Smart Object

  4. Apply Unsharp Mask to help retain the detail

  5. Apply a levels adjustment layer

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  1. Apply a threshold adjustment layer

Tweak 4, 5 and 6 if necessary to try to keep maximum detail in shadows and highlights.

Before final output, convert to bitmap mode, and export as BMP. For peace of mind, request a proof before going to print.

Here’s the example, showing the unsharp mask settings. Note that I put the adjustment layers in a group so I could easily toggle them on/off to check with the original.

enter image description here

100% detail

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Attribution
Source : Link , Question Author : WillS , Answer Author : Billy Kerr

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