Script Analysis - X-Height

OK, so the x-height is 7mm, or 5 nib widths. (As Michelle Brown's/Patricia Lovett's Historical Source Book for Scribes says and my re-measurements have confirmed)

There's only one small problem.
7/5 = 1.4, not 1.5

Looking at pen nib width charts

http://callibeth.blogspot.com/search/label/pens

well - I don't have a Koh-I-Noor technical pen and I don't know if they come in left handed.

This other chart doesn't even HAVE a 1.4 nib width shown.

		William Mitchell					Line Height Measurements (in millimetres)
Millimetres	Osmiroid	Right Hand	R/H Italic	Speedball C	Hiro	Brause	3 nib widths	4 nib widths	5 nib widths	7 nib widths
0.50 mm	Ital Ext Fine	Size 6	Size 5	Size 6	Size 5	½ mm	1.5 mm	2 mm	2.5 mm	3.5 mm
0.60 mm	–	Size 5	–	–	–	–	1.8 mm	2.4 mm	3 mm	4.2 mm
0.75 mm	Italic Fine	Size 4	Size 4	–	Size 4	¾ mm	2.25 mm	3 mm	3.75 mm	5.25 mm
1.00 mm	Italic Med	Size 3½	Size 3	Size 5	–	1 mm	3 mm	4 mm	5 mm	7 mm
1.25 mm	Italic Broad	Size 3	Size 2	–	Size 3	–	3.75 mm	5 mm	6.25 mm	8.75 mm
1.50 mm	B2	Size 2½	Size 1	Size 4	–	1½ mm	4.5 mm	6 mm	7.5 mm	10.5 mm
2.00 mm	B3	Size 2	–	Size 3	Size 2	2 mm	6 mm	8 mm	10 mm	14 mm
2.50 mm	B4	Size 1½	–	–	Size 1½	2½ mm	7.5 mm	10 mm	12.5 mm	17.5 mm
2.75 mm	–	–	–	–	Size 1	–	8.25 mm	11 mm	13.75 mm	19.25 mm
3.00 mm	B5	Size 1	–	Size 2	–	3 mm	9 mm	12 mm	15 mm	21 mm
3.50 mm	B6	Size 0	–	Size 1	–	–	10.5 mm	14 mm	17.5 mm	24.5 mm
4.00 mm	B8	–	–	–	–	4 mm	12 mm	16 mm	20 mm	28 mm
5.00 mm	B10	–	–	Size 0	–	5 mm	15 mm	20 mm	25 mm	35 mm

28 December : There is another nib width comparison chart in the SCA_S&I files. It gives (only) an Osmoroid BR as having a 1.4 mm width.

So I'm going to stick with the 1.5mm width Brause I have.
Meisterin Katarina Helene suggested that of course they were cutting quills back then, so had more opportunity to create a 1.4mm wide nib.
The letters will only be the tiniest bit thicker and more cramped. But since I know - if I do copy a page of writing from one of the images I have of the Bedford Psalter on a transparent sheet, and hold it over the original - I'll know (one reason) why the letters aren't exactly the same.