controlling every pixel

[Christiane5E2D]

Hello,

I am working on a project for industrial ink-Jet-Printing and need to create patterns (monochrome Bitmaps) for printing. The sizes and position of the features is very important and the resolution is quite high (1050 dpi, pixel size 25 µm). If I convert our AutoCAD files to bitmaps, there will be rounding and shifting, so I started to use eps to take control over the pixels. Now I ant to know, if it would be possible to create the pattern with Adobe InDesign?

[rob day]

Now I want to know, if it would be possible to create the pattern with Adobe InDesign?

Not in any practical way, InDesign is not a bitmap application.

If I convert our AutoCAD files to bitmaps, there will be rounding and shifting

Is the inkjet output at 100%? At 1050ppi how would shifting be visible when the page gets RIP’d for inkjet output? If you think it would be, you are not limited to a 1050ppi bitmap. A CAD drawing’s vector lines could be opened into Photoshop at a higher resolution—it could be the printer’s resolution. The vector drawing as a PDF, opened into Photoshop at 2880ppi as a grayscale, and converted to Bitmap with the Output set at the same 2880ppi Input resolution.

[Christiane5E2D]

Thanks for the input. My inkjetter is printing with 1050 dpi, that is already the print resolution. The Pixel size is 24,203 µm and that is not going very good with the size of my features, so there has to be some rounding. But if I just let the program make the rounding during conversion from vector to bmp, my features tend to be not as big as I want them. So I want to use eps, but maybe there is a graphical editor that can make my life easier?

[rob day]

But if I just let the program make the rounding during conversion from vector to bmp, my features tend to be not as big as I want them.

Why not print the vector drawing? Do you mean the CAD drawing’s line weights are too fine to print and you are converting to bitmap in order to get a heavier line weight?

[Christiane5E2D]

I can not print the vector drawing. inkjet printing is digital, either the dot gets printed or it doesn't get printed. So I have to tell the printer which dot to print and which not. The printer only takes monochrome bitmaps or programmed eps files. Maybe I should explain some more, it is not a standard desktop printer, and I don't print normal graphic designs, I print the trenches between dies on a silicon Wafer with an etch-stop medium (hot melt wax). I have to stay inside +/- 25 µm for the feature size and positioning regarding the center of the wafer, and one pixel being already 25 µm there is not much margin for error in the print layout. Since there are mechanical and optical issues as well, I have to get the print layout as perfect as possible. So in the end I either learn to write eps code or I find a good graphical editor that lets me edit with an underlying pixel grid. 

Do you mean the CAD drawing’s line weights are too fine to print and you are converting to bitmap in order to get a heavier line weight?

By @rob day

I do not have fine lines in my layout, I have filled squares with rounded egdes and open, not printed spaces inbetween (like my profile picture, the black is printed, the light is not printed - but that's not made with inkjet, but with screen printing).

[rob day]

Got it. What’s the typical output’s pixel dimensions? Can you share a sample CAD drawing?

InDesign’s tools draw vectors. You could setup a document to the output’s pixel dimensions and with the ruler units set as Pixels draw 1x1 pixel black squares snapped to the grid, but I doubt that would be easier than editing a Bitmap mode image in Photoshop.

[Scott Falkner]

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@rob day wrote:

You could setup a document to the output’s pixel dimensions and with the ruler units set as Pixels draw 1x1 pixel black squares snapped to the grid, but I doubt that would be easier than editing a Bitmap mode image in Photoshop.

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InDesign doesn’t have pixels as a unit. Do you mean OP should do this in Photoshop?

[rob day · Accepted solution]

The Document Setup’s Width and Height can be defined in Pixels and Rulers can be set to Pixel units in Preferences

If the Document Setup is set to the desired output pixel dimensions, it could be exported as a PNG or JPEG image format at 72ppi and the pixel dimensions in Photoshop would match.

@Christiane5E2D is looking for a 1-bit Black & White image, so as an example the document grid could be set at 1 Pixel increments, and 10x10 pixel rectangles could be step and repeated with 1 px in between. An export to PNG at 72ppi would export the grid with the same pixel dimensions:

An Export at 72ppi exports the page at its specified pixel dimensions

In Photoshop the square’s pixel dimensions match the InDesign rectangle dimensions:

The Photoshop image can be resized to any Resolution without changing the pixel dimensions, it doesn’t have to be left at 72ppi export resolution:

[Christiane5E2D]

wow, thank you very much for the detailed answer! Yes, I will definitely try this. My pattern looks a lot like the example you made there, so it is a good approach. This really helped.

[rob day]

If I convert our AutoCAD files to bitmaps, there will be rounding and shifting, so I started to use eps to take control over the pixels.

Also, have you tried converting the CAD drawings with Anti-aliasing turned off? That would have an effect on the pixel positions.

[rob day]

Also, in case it isn’t obvious there are a few other things to watch out for. InDesign will let you work in partial pixel sizes, so you’ll want to setup a 1 pixel grid and snap to the grid. For example if I offset my sample grid by .5px and allow anti-aliasing, this can happen—the tiles on the right are offset .5px and anti- aliased:

A conversion to Bitmap Mode would do this:

And, your black pixel fills should be 0|0|0 RGB and not the print default 0|0|0|100 black. CMYK black is not usually absolute black, so you might get this on the conversion to Bitmap mode: