How to export a drawing in good quality?

Hi,

over the past few days I worked myself into LibreCAD 2.1.3 to created a technical drawings for a hand rail. The drawing turned out quite nicely. Now it was time to get it printed.
Since I do not own a A3 printer I wanted to export the file to PDF to have it printed elsewhere.

While the image in LibreCAD looks like this:


The PDF export turned out a little different. I was a bit disappointed about it.
The exported lines were rather coarse.
The biggest problem is that the geometry for the 5mm holes are lacking detail, because half of the dots for the dotted lines are missing and are way to thick. Those are the smallest dots in LibreCAD (tiny dots). So I ran out of ideas on how to get a more detailed export.


I tried to "Export as image" and chose SVG. But the result was even worse than the above image. Now the numbers where all mangled.


Exporting as JPG creates a half way decent image, but the line widths seem to be off. Everything is super thin and the lines have compression artifacts.


Exporting to TIFF creates an image without artifacts but at a size of 200MB per export, where the line widths still look too thin.
The image resolution for both images is 10080x7128px (~430DPI) which should definitely be high enough to create a smooth and close to perfect image. A 0.35mm line should be 6 pixels wide, but the thickest line 3 pixels which look like this:


When exporting the image I had to choose at least a resolution of 3 to get a half way decent image. Anything bigger than 3 creates an empty image.

Any help on how to export a nice quality image are greatly appreciated.

Thank you a lot in advance...

Export to pdf is the right way to to print somewhere else.
Line weights are only shown right on the screen in drawing mode when the intended scale is 1:1, for other scale check in Print Preview. For line type pattern not even Print Preview is reliable, it changes if you zoom around in it. It will print out on paper (or into a pdf) at one certain way, regardless of scale. You can print out this A4 sample sheet as reference:linetypes.pdf
There is no way yet in LibreCAD to scale or manipulate these linetypes, or to define your own. Yes, for dot tiny it would be useful to have a finer version available.
Edit: have you used Print Preview at all? Only this way you get best control of output.

Yes, I have used print preview. I even created a frame so that the drawing fits perfectly onto an A3 at a scale of 1:4.
I have noticed too that the dot spacing changes when zooming in and out in print preview.

Thank you for your answer.

Unfortunately I'm at the same point I was this afternoon. I will most likely edit the printout prior to handing it over.

" I will most likely edit the printout prior to handing it over."
Interesting. How will you do that?

I will remove the slanted lines from the drawing and add them with a pen on the printout later on.
In the end it will probably not be the most beautiful drawing, but one can see how it is supposed to look.

For a clean looking printout you may consider to substitute the dotted line with a continuous grey line, to indicate a hidden line.
Or, if you like to fiddle around, you can edit the pdf in Inkscape. You will have to ungroup the drawing several times until you get to the single entities. You need to have the intended dotted line as a continuous one, else every dot will be an entity. Then edit the linetype of contour. Just tested, it works. Have fun!

You could also draw solid lines in an interrupted way to create the dotted lines (say 1 mm long lines spaced by 1 mm). Then I would be as per your preference. The scale operation will not affected this length and space of lines. Quick and dirty...

Good idea. You could even really use points instead of short lines, if you prefer. With Move/Copy - Multiple Copies you can make easily a dotted line of any length. You can reuse that again and again, copying, moving and rotating it as desired. You could even make a collection of custom linetypes and save it as an extra drawing. Or as blocks. So many possibilities...

I figured out a way to create a nice looking PDF of my drawing at a scale of 1:4.

Under "Current Drawing Preferences" I choose custom Paper Format:


My current size is 4x as big as A3, which matches my scale of 1:4.
I exported this drawing of 1189x1681mm to PDF 1:1:


Then I open it up in Acrobat Reader and printed it again to A3 using PDF24. Under "Page Sizing & Handling" I chose "fit".


The resulting PDF is A3 and shows every detail :-).