Halftone and Color Separations

[titanif]

Hello.

I'm working on a silkscreen project and need some halftone gradients, preferrably auto generated if it's in Xara...

Is this feature somewhere to be found in export? I'm not sure exactly where to look. I'm fine with registration marks and such, I just put on my own for reference, but I'm not sure how to go about 'faking' halftone patterns if I have to do that, assuming the likelihood of halftone exports not being in Xara. I'm using 15/X btw.

[handrawn]

there is no halftone export in xara

as for 'faking it' - here are a few threads I googled:

https://www.google.com/search?client...+halftone#ip=1

[Acorn]

No idea if this is of any use.
I just built it: CSS - Half-tone.xar

Ctrl-click on the image and Replace Photo.
Whatever you do, the image must keep the Image Filename photo.
I cannot recall if this exists in XDPXv15. Do ask if it isn't, there is a workaround.

A mouse-over shows the original.

Xara has yet to fix when an image changes, the Image Filename gets suffixed.
You have to Preview a second time!

In Website Head, most of the variable to tweak things are under :root.

My test piece:



Original:



Acorn

[gwpriester]

First: this photo will not drag and drop into DPro+. Once I do manage to get it into DPro+ it locks up the program and I have to restart Windows to get the program to close.

Second: this is a halftone effect and not a halftone.

The difference is a halftone only contains solid black over white. The size of the individual black halftone dots become larger or smaller to represent the in between tones.

https://en.wikipedia.org/wiki/Halftone

[handrawn]

takes me back to letratone....

and ben day, although that is dotty in a different way

[Acorn]

First: this photo will not drag and drop into DPro+. Once I do manage to get it into DPro+ it locks up the program and I have to restart Windows to get the program to close.

I distinctly said Replace Photo. The image is soft-grouped so dragging may not work and you probably will have lose the Image Filename.

I have just tried Ctrl+Select the current image and then dragging the new image onto it with no issue. Repeated several times (XPro+).

Second: this is a halftone effect and not a halftone.
The difference is a halftone only contains solid black over white. The size of the individual black halftone dots become larger or smaller to represent the in between tones.
https://en.wikipedia.org/wiki/Halftone

To get pure black dots, you just ramp up the Line Contrast:

:root {
--dot-size: 0.25em;
--line-color: #000;
--line-contrast: 2000%;
--photo-brightness: 80%;
--photo-contrast: 150%;
--photo-blur: 2px;
--blend-mode: hard-light;
}

The same WP article also covers the dot shape, round, elliptical and square.
The parameters chosen can be adjusted for these.

500% zoom on original with above settings.


Yet to try colour separation. Up to now I have used ImageJ2, which is a massively powerful tool.
Who knows? Xara might have a few tricks lying around.

Acorn

[gwpriester]

Thumb up

[handrawn]

@acorn

interesting - how do I export the halftone as an image file ?

I tried both export website look in folder, and screen save from browser - neither worked, though I may be doing something wrong, not being a web-doc guy... thanks

[Acorn]

@acorn
interesting - how do I export the halftone as an image file ?
I tried both export website look in folder, and screen save from browser - neither worked, though I may be doing something wrong, not being a web-doc guy... thanks

handrawn, Xara has still failed to handle post-processed images. I revert to A3 Landscape PDF printing from the browser or a screenshot.

Acorn

[handrawn]

if I print to PDF I get greyscale, not halftone - but based on what you have previously said, am I right in thinking this does not work in firefox?

if so, can I view it from xara in another browser without changing my windows default,which is not an option at the moment...