Export to pdf yields wrong dimensions

[Mats_Knutsson]

Hi,
It's small but however I don't understand where the "clutter" comes from.
/Mats

[DGSketcher]

You have a valid question Mats, fully supported by the "paperless" argument. What accuracy should we expect from PDF? However, there is that fundamental disclaimer that tends to appear on most drawings "Do Not Scale from these Drawings" and "Always work from figured dimensions. I believe the same is relevant to digital documents. As suggested above the likes of Bluebeam may give accurate feedback from vector drawings but the disclaimers should still apply, particularly if the publisher is less than perfect with their drawing workflow.

[Erwin Edel]

I would argue that PDF is the 'wrong' file format for checking dimensions etc, while I still recognise that a lot of software out there went this route.

Personally I always ask for DWG and/or IFC from third parties to do any clashing / checking of dimensions, as I do not trust the inaccuracies of the PDF format.

I do like PDF as a format of how are things supposed to look, since it handles fonts fine. DWG are also a pain in the ... to print without pensets etc and really a relic of the dark ages in this regard!

[Minh Nguyen · Accepted solution]

Dear All,

Thank you very much for your opinions about this issue!

I looked into our system and Mats's question was answered by our colleague. Here is our developer's explanation:

1. The standard error tolerance in Archicad is 0,01mm, which seems absolutely tolerable in a building. Most of our codes don't work more precisely than this.

2. If you print to a virtual PDF printer, the difference will be larger. In the print workflow precision is less important than drawing the whole requested area, including the lines on the edge. For this reason, we use a pixel-size rounding down in the page size, so in the worst case, the page content will be smaller a little bit. The size of the difference is the same as one or two pixel's size. Therefore the proportion of the difference depends on the resolution and the page size as well, but generally is 0.1-0.2%. On a printed paper the one pixel difference on a whole page is totally unrecognizable. However if you print to a virtual printer and then measure the size, you can find it.

If you want to bring the PDF back to Archicad and 0.1-0.2% difference is not acceptable, we recommend directly save the layout/view as PDF or use Publisher function instead of a virtual printer.

I hope this explains the situation. Please let me know if you have any questions!

Best regards,
Minh