FIBROUS MATERIALS 9
but we have no reason to doubt that esparto papers produced by modern
methods are reasonably permanent.
Though esparto may be 'beaten' to a certain extent, the action of the beater
roll is confined mainly to brushing or drawing out the fibres, very little 'cutting'
being done. Spanish is shorter in the blade than African, smoother in surface,
more springy and shows superior strength and colour. It stands treatment
better, yielding a whiter and cleaner fibre.
It may be used in thin writings and banks where African would be practically
useless. The latter comes to the mill in hydraulic-pressed bales of about 3 cwt.
each, and must be stored under cover. Care must be taken to isolate any bales
that are wet (which occurs very often to 'deck cargo' during a voyage). These
may heat and take fire and should be used immediately if possible.
Spanish is delivered more loosely packed, bound with esparto ropes, and
for this reason is less liable to heat and rot. It is usually in a drier condition
than African.
Esparto papers are distinguished by their refined silky texture and bulk and
close uniform surface or finish. This latter quality is their most outstanding
point, and makes them eminently suitable for fine printings and other papers
that are required to take a fine impression from plates. The best body papers
for surface coating are made mostly from esparto. It is not a fibre that will
run well over the machine without a stiffening of wood pulp. Its 'greasy*
nature and shortness cause it to stick to the press rolls, causing breaks and waste.
A charge that has been too harshly treated in boiling and bleaching soon makes
itself known in the machine room. In this connection it has been found that
granite press rolls are a very great advantage.
It is a very absorbent fibre, taking up and retaining a great deal of resin size,
and may be made into quite a hard, 'tinny* paper, very suitable for E. S. Laid
and Wove Writings. The fine surface obtained on some of the cheaper rag
papers is due to the small percentage of esparto paper 'broken' used as a filler.
Esparto fibre is very easily water-marked, is very regular in expansion and
contraction, and is generally considered the best for making papers that must
be accurately and finely printed and cut. For the 'offset' printing process esparto
papers are unsurpassed.
A peculiarity of this fibre is that after being beaten ready for the machine
it very readily runs into knots or balls, which the strainers (even with 3 to 2\ cut
plates) are unable to keep back. These appear as clear spots in a high finish,
and utterly spoil the paper, so that if a chest of stuff is affected in the least degree
there is nothing to be done but to run it off at the press rolls and re-pulp. This
is caused by too much agitation in the stuff chest, either by the agitators being
run too quickly, or by the stuff taking too long to work out. The rubbing on