Ink bottles capacity

The results of the ink bottle capacities are summarized in the table maintained on this page. What we measure is not the total capacity of the bottle (which will be marked for reference) but the capacity to allow the pen to be filled leaving the lowest residue when the contents are exhausted. The purpose is to check how reliable the claim to fill "to the last drop" is.

Measurement mode

The pens used in measurements.

The measurement methods are described in this article (in italian) on the blog and discussed in this topic (in italian) on the forum, where the results of the various measurements are also explained. This page is mainly used to report the summary of the results, we will limit ourselves to a brief summary.

We used two pens (a Pelikan 140 for medium to small size and a Duofold De Luxe for medium-large size) to progressively empty the bottle of ink or the inkwell under examination by repeatedly filling them. The four methods to fill the pen from the bottle defined in the following paragraph were used, weighing the remaining residue for each of them with centigram accuracy using a balance.

We regarded (apart from the last case) as the limit of passage between one filling mode and another the step in which, maintaining that mode, the pen cannot be filled in a significant way, assuming as "significant" the amount of 0.8 ml of ink, basically the content of a short cartridge.

Definitions

The table lists the capacities for the four different filling modes:

normal filling: it is loaded with the bottle is placed horizontally in the ordinary position where it is also resting, inserting the pen from the mouthpiece without any shrewdness. This is the normal way to load a pen, the simplest and most convenient.
careful filling: it is loaded with the bottle is placed horizontally in the ordinary position in which it is also at rest, inserting the pen from the mouthpiece, but being careful to position it in the most appropriate way (for example, tilting it to get to the corners) to improve the draught. This mode is very close to the normal one, but requires a bit of attention and is less comfortable.
specific filling: it is loaded using the specific characteristic of the bottle that allows (or declares to allow) to make the most of its ink capacity. Usually there is something more to be done than inserting the pen into the mouthpiece and filling (and may increase the risk of overturning), and the mode may be more uncomfortable or cumbersome.
acrobatic filling: it is loaded using any method that allows as much ink as possible to be recovered from the bottle, using any type of stunt (hence the name). Generally, if it exists, it is an uncomfortable and risky mode (another reason for the name) that is not worth using.

Results

In the following table are listed only the value of the residue. For all of them an experimental error of 0.02 ml is applied with respect to the measurement (due to the systematic error of the balance, which has an accuracy of the centigram), but given the relative arbitrariness of the above definitions, consider a real accuracy of an order of magnitude less (i.e. 0.2 ml)

Bottle	total	link	Pelikan 140				Duofold
Bottle	total	link	normal	careful	specific	acrobatic	normal	careful	specific	acrobatic
Pelikan 4001	30 ml	[1]	6,42 ml	2,51 ml	1,30 ml	0,56 ml	12,16 ml	6.72 ml	2,58 ml	0,77 ml
Montblanc (old)	50 ml	[2]	21,27 ml	--	1,63 ml	0,27 ml	23,33 ml	--	2,36 ml	0,84 ml
Visconti (old)	75 ml	[3]	2,17 ml	2,17 ml	2,17 ml	0,63 ml	2,62 ml	2,62 ml	2,62 ml	0,46 ml