<div class="gmail_quote">2009/1/28 Ian Britten <<a href="mailto:britten@caris.com">britten@caris.com</a>> <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Hi all, I'm still struggling with how to best handle hairlines, and am wondering if anyone could offer some guidance/suggestions... In my early work, I used a device thickness of 1.0/300.0 (converted to user) as the thickness when I needed to draw these types of lines. This seemed to work ok when outputting to PDF.  However, when I output to an image (PNG), the lines don't visually appear (Too thin?). OTOH, if I use a device thickness of 1.0 (converted to user) as the line thickness, the lines look as expected in the image output. Unfortunately, this is far too thick in the PDF output.  :( Long story short, it seems that I'm going to have to examine the type of surface I'm using, and use different numbers for the thickness accordingly.  IMHO, this seems to defeat one of the abstractions that Cairo touts - Namely drawing the same way to any surface type. Thus, I figured I'd ask, and see if there isn't a better technique.</blockquote><div> On the other hand, if Cairo had hairlines it would defeat another of the great abstractions: consistent results independent of resolution.  Sometimes it is deceptive when hairlines in a low-resolution display to appear thicker relatively to other (non-hairline) lines, while thinner (almost too thin to see) in very high resolution displays. That being said, I used to be more against hairlines.  Nowadays, after using goocanvas with zooming I have been bitten by this problem as well: when  I zoom out a lot, my lines eventually disappear. </div></div> -- Gustavo J. A. M. Carneiro INESC Porto, Telecommunications and Multimedia Unit "The universe is always one step beyond logic." -- Frank Herbert