MobileRead Forums - View Single Post - Probably bug

Simons Mith · 10-16-2020, 12:37 AM

I have an epub I'm converting to pdf. The Calibre converter's doing okay, really, but I decided for best results to create a customised epub and convert that. The document uses 'thin' 'medium' and 'thick' lines which are 0.25mm, 0.5mm and 1.0mm - those were round numbers chosen to make some CSS box sizes neater.

(css sample:

div.large_cap {
background-color: #FFFFFF;
border: 0.25mm solid #222222;
color: #5588FF;
line-height: 12.5mm;
text-align: center }

i.e. a decorative box round a drop cap)

But the 0.25mm lines vanish entirely from the PDF output, although they display fine in Calibre when I view the epub, and also when I view the relevant chapter html file in a web browser. So I don't think they should disappear in the pdf. When you print at 360 dpi, 0.25mm is would be about 3 dots wide so they should print OK except they're getting nobbled in transit. So I think there's a rounding error in Calibre. This is because 'one pixel' is 1/96th of an inch (ish; I know some caveats may apply), and that's 0.26mm. Seems I unknowingly chose a round number juuuust below that, so no thin lines for me!

I'd be glad to log it as a bug - can anyone confirm it?

Is there a config setting I've missed where I can set the minimum line thickness to some lower value?

10-16-2020, 12:37 AM	#1
Simons Mith Member Posts: 23 Karma: 10 Join Date: Oct 2020 Device: none	Probably bug - Thin lines vanishing I have an epub I'm converting to pdf. The Calibre converter's doing okay, really, but I decided for best results to create a customised epub and convert that. The document uses 'thin' 'medium' and 'thick' lines which are 0.25mm, 0.5mm and 1.0mm - those were round numbers chosen to make some CSS box sizes neater. (css sample: div.large_cap { background-color: #FFFFFF; border: 0.25mm solid #222222; color: #5588FF; line-height: 12.5mm; text-align: center } i.e. a decorative box round a drop cap) But the 0.25mm lines vanish entirely from the PDF output, although they display fine in Calibre when I view the epub, and also when I view the relevant chapter html file in a web browser. So I don't think they should disappear in the pdf. When you print at 360 dpi, 0.25mm is would be about 3 dots wide so they should print OK except they're getting nobbled in transit. So I think there's a rounding error in Calibre. This is because 'one pixel' is 1/96th of an inch (ish; I know some caveats may apply), and that's 0.26mm. Seems I unknowingly chose a round number juuuust below that, so no thin lines for me! I'd be glad to log it as a bug - can anyone confirm it? Is there a config setting I've missed where I can set the minimum line thickness to some lower value?