I forget where now, but we've discussed this Renaissance wax on FPN insofar as it leaves a hard and fairly durable coating on the pen, and it's this hard coating that is responsible for the shine - and as far as I was aware the main downside, as mentioned above, appeared to be that the coating was difficult to remove and required something like white spirit to do so - although why you'd want to remove it I'm not sure. Have to say I wasn't aware of the dangers when used on BHR pens.
I notice that my small tin (65 ml.) of Ren. Micro-Crystalline Wax, from Picreator Enterprises in London, still carries the blurb about it being .......
"Refined waxes blended to a formula used by the British Museum.........". - although exactly what the B.M. use it for the tin doesn't say. I suspect ceramics, leather and other materials that have sensitive surfaces or coatings etc. There is no mention on the tin of a solvent being present in the product, but that doesn't guarantee there isn't one in there somewhere, and whilst the wax can be seen to darken leather immediately, and they dry almost as quickly, it does seem to suggest a solvent it present to carry the wax into the leather.
I've put this wax on bookbinding leathers for some time now and they haven't yet fallen apart or developed red rot, which is the scourge mainly of C19 leathers, where quite literally the leather turns to dust and crumbles away - mostly it seems on red leather. Prior to mid C20 and especially in the C19, leathers were treated very harshly with chemicals, by the tanners and others in the trade, and we now know this created a built in destruction that made itself apparent some decades down the line, plus leathers were pared too thin to stand up to hard use - all done in the name of profit margins, since commercial bookbinding was big business 100 years or more ago. Also, part of this cheapness route was to use sheepskin rather that the more expensive and heavily grained goatskin, so another reason for the leather to decay quicker.
The problem was the sulphuric acid used to treat the leather prior to using aniline dyes, which looked good at the time, giving a greater depth of colour penetration, and with good preservative properties on wet leather. Now I believe the leathers are vegetable tanned, and much of the naturally occurring properties of leather are no longer destroyed by the acid, and so these skins remain durable for far longer.
This problem with leather didn't happen with vellum, and most of the early monastic books, although somewhat crinkly in appearance remain strong and good for another few centuries.
One very well know exception to an historic book suffering leather deterioration is The St. Cuthbert Gospel of St. John, which in very recent times cost the British Library the thick end of $12M. This smallish tome owes it survival to the fact that initially it was buried with the man himself around 698 A.D., and only much later removed around 1104 A.D. - it survives today looking very much as it probably did many centuries back, with the vellum folios in very good condition and the goat or pigskin cover looking very healthy. So moral of the story is if you want to look after you books, have them buried with you
People want a shine/sheen on the precious items, and any product that gives that sort of result quickly is going to be popular - despite hidden dangers that may lurk someway down the line.
As far as leather goes, it's a natural product that for longevity needs to both breath and remain supple. If you block the pores with a impermeable coating, that's fine if it rains, but no good for applying moisture via creams or waxes, which will stop the leather drying out, cracking and breaking down over time.
Not a problem for pens of course, and I've applied Ren. Wax to many f.ps. with terrific results of enhanced depth of colour and a shine to die for, but when I read about the possible solvent issue, plus the fact that removal is difficult, I stopped using it.
I've gone over to using MICRO-MESH ® liquid abrasive products, which are water based, and contain ultra fine grits in grades around the size 12,000 plus to give a shine - alternatively, coarser grit papers and liquids can be used prior to that depending on the extent of surface defects on the pen, which need to be removed. Since this product leaves absolutely no coating on the pen, it's effectiveness to shine the plastic is only as good as the surface of the pen, and some preliminary smoothing is probably essential, at least on a knackered pen.
P.S. re the problems of putting water on some types of pen plastics, it might be wise to seek an expert opinion before applying the MICRO-MESH product since the carrier is of course water.
Edited by PaulS, 14 December 2016 - 15:28.