TR: A question about inks
-----Message d'origine----- De : Jack Brubaker [mailto:jack@jackbrubaker.com] Envoye : 15 decembre, 2006 14:07 A : alt-photo-process-l@usask.ca Objet : Re: A question about inks Thanks Gawain, Great information. Jack > From: Gawain Weaver <gawain.weaver@gmail.com> > Reply-To: alt-photo-process-l@usask.ca > Date: Fri, 15 Dec 2006 10:22:42 -0500 > To: alt-photo-process-l@usask.ca > Subject: RE: A question about inks > > The distinction here is probably similar to that between today's inkjet inks > and pigment inks. Inks are much smaller, often individual dye molecules or > very small aggregates of dye molecules (~3-20nm in size) that are soluble > in their medium, while pigments inks are larger aggregates (~100-1000nm or > larger) of the same colorants, but due to their size are no longer soluble > and so form a dispersion rather than a solution. Pigments for inkjet would > be on the smaller side of that range, perhaps 100nm, while for offset > printing the they might be around 500nm. The individual ink molecules in > these aggregates are not by themselves any more fade resistant than before, > but there are a lot more (so it takes longer to fade), and there is a > certain added stability achieved in aggregation. > > The old simplification of ink=organic and pigment=inorganic was very > convenient, but it certainly does not apply in today's world. Pigment is > really just an indication of a larger particle. > > Gawain Weaver > > > > -----Original Message----- > From: Jack Brubaker [mailto:jack@jackbrubaker.com] > Sent: Wednesday, December 13, 2006 12:00 PM > To: alt-photo-process-l@usask.ca > Subject: Re: A question about inks > > Can anyone tell what pigment dyes are? > > Jack > > > > > |