What is this padding?

Help
1

Hi,

if I do this in dot:

  graph G {
    bgcolor=red
    margin=0.0
    pad=0.0
       a [
         shape=square
         fillcolor=green
         style=filled
       ]
   }

I get a square that fills the entire image - there is no background visible anymore.

However when I try this with an html-node like this:

  graph G {
     bgcolor=red
     margin=0.0
     pad=0.0
       a [
        shape = none
        label = <<table bgcolor="green" cellspacing="0" border="0" cellborder="1">
                    <tr>
                       <td>a</td>
                    </tr>
                </table>>
    ]
   }

I get a green square with a lot of red padding.

Where is this padding (if this is the right term) coming from and how can I get rid of it?

Many thanks!

2

[Whew, this was a head-scratcher, but after many experiments …]
Change shape=none to shape=plain.

The “problem” is that shape=none keeps the default node height and width and that node space is then painted the graph bgcolor of red.
As an experiment, try shape=rect

3

Good find, many thanks.