It might have been posted before – i am a textpattern newbie – but nevertheless:

To modify the comment input field lengths (in textpattern 4.0.3) you need to – open textpattern/publish/comment.php – go to line 65 – 67.

you’ll see this:
65 ‘isize’ => ‘25’,
66 ‘msgrows’ => ‘5’,
67 ‘msgcols’ => ‘25’,

explanation:
65 ‘isize’ => ‘25’, // length of email / name / http fields
66 ‘msgrows’ => ‘5’, //# of rows in comment input
67 ‘msgcols’ => ‘25’, // # of cols (letters) in same field

i set my version to:
‘isize’ => ‘25’,
‘msgrows’ => ‘15’,
‘msgcols’ => ‘40’,

which gives anyone commenting more space to type longer text while still having a good overview about the complete comment.

any other mod, like styling the fields (no border, background-color, text color and text font parameters) can easily be done by modifying the appropriate css entry – or making a custom one up yourself.

don’t forget: any textpattern update will let you have to do this mod again.
nevertheless: happy modding!

jayrope / kliklak.net / berlin