Half-tone dot screening

[David Aynardi]

Still no satisfactory answer to this query.

To repeat my old question: Is there a way to screen portions of a drawing causing the line-work to print in a dot-pattern similar to the Benday dot screen used by the printing industry. This is not the same as changing the lines to color = gray. Using color produces unreliable product, especially if the resulting hard copy is xeroxed, which frequently happens. Screening, (which is actually all black) better withstands photocopying and is immune to color synchronization problems.

Working drawings are frequently sent out of office in electronic form, and frequently exchanged with consultants who work in ACAD. If everyone has screening capability, we can all produce consistent results. (My 20% screen looks like my consultant's even though produced with different software) If we rely on color rendition, there is no hope.

This is a very big deal to anyone who is trying to produce drawings for remodel work and is a problem which was effectively solved by the competition many years ago. (Acad and Microstation have always had screening capability).

When I've asked about this in the past, the response has veered into a discussion of printing in color (gray). I need to know if screening (NOT COLOR=GRAY) is possible within VW or if there is a work-around OTHER than using gray to produce a real dot-screen pattern.

[ 01-11-2005, 12:54 AM: Message edited by: David Aynardi ]

[CipesDesign]

Hi David, I'm not sure whether this will be helpful but....when you hit command P (or go to file print) there is usually an advanced setting which allows you to print the entire document as "B & W high quality halftone". I do this frequently for the purpose of better photo copies.

[P Bartoli]

Out of curiosity, how ACAD and Microstation achieve half tone printing?

If you're on Mac OS, I know you can achieve B/W dot printing with MacPlot plotter driver, if this's what you're after.

BTW, are you exchanging digital files or paper drawings with your partners?

[David Aynardi]

In response to Paolo Bartoli's questions:

1, "how ACAD and Microstation achieve half tone printing?"

At a detailed technical level, I don't know, (I'm not an IT guy), but as a practical matter, we could identify a layer to receive one of several degrees of screening (40%, 60% etc). Anything drawn on that layer would be rendered in that halftone screen when plotted. I was working in Microstation, our Acad-based consultants had the same capability.

2: "are you exchanging digital files or paper drawings with your partners?"

We communicate by sending DWG or DXF files to our consultants for them to incorporate into their work. In my former MStation life, once we agreed on which layers would get which screens, it was automatic and not impaired by the translation process. We could translate our drawing to DWG, our consultants could print the ACAD version of our drawing, apply their version of the 40% screen, and get the same result that we had in the original.

This capability was old news and was taken for granted in the MS and ACAD world. Now I am trying to do a big remodel job in Vectorworks, and discover that I have nothing but sharpened sticks to draw with.

[ 01-11-2005, 01:33 AM: Message edited by: David Aynardi ]

[David Aynardi]

PS to my previous reply to Paolo Bartoli:

Paolo's message states that "you can achieve B/W dot printing with MacPlot plotter driver".

This might be what I am looking for. Is there a way to tell the MacPlot driver what part of the drawing gets the dot treatment, or is it indescriminately applied to the entire document?

[ 01-11-2005, 01:11 AM: Message edited by: David Aynardi ]

[David Aynardi]

In response to Peter Cipes' comment above:

My problem is not how to obtain good half-tone reproduction on our plotter (we have good luck at that). The problem is to produce a robust gray that can survive copying and re-copying by malevolent idiots using badly-maintained copy machines. To this end, a very coarse dot-screen is best because the black dots remain distinctly unlike any other part of the drawing no matter how poor the reproduction.

[Yovav]

If I understand your problem and if you are using HP machine try this:

Open print dialogue box, go to "properties" button, select the "options" tab, and select the "manual color" or "color as grayscale" buttons. Then click the "color control" button and in the "halftoning" pop-up menu select "cluster".

HP help files for the print drivers say that: "Cluster halftoning places dots of ink in clusters to produce complex graphics and documents that are to be photocopied."

If you are using a printer from another brand try searching for a similar option, in the driver's preference options

[RubenH]

Why you don't use patters in combination with colors? When you set the prefs to B/W you have dots, instead of a solid white. The first six patterns next to the black could help, because they can be considered as densities of gray.

[LarryAZ]

Yovav,

What HP printer are you using? On my 130nr I can print grayscale using the Quartz filter but I don't have a properties button or anything about clusters.

I would love to be able to this. The copier I use has very few shades of gray and beautiful renderings come out as dark globs when copied. The old Apple drivers used to call this "dithering".

[Yovav]

Hello Larry

The preference options I'm talking about are relevant to all the range of the DesignJet plotters. I'm using those over windows, and maybe over the Mac side drivers act differently. Anyway I think that checking this subject with HP could be more helpfull - the answear should be at the driver side of the formula