right nigel
now am i correct that polypropylene is acid free? if so this would be a good deal,100 for £2.50 with free postage
http://www.ebay.co.uk/itm/A4-Polypropylene-Clear-Plastic-Punched-Pockets-Folders-Filing-Wallets-Slee...
got this from a aftal autograph shop that deals in preservation,apparently polyester is the answer,, a4 pockets are a £1 each,,if,,also had a word with the owner,he ensures me that paint pen will not lift onto the polyester ever
Crystal Clear Polyester
Conservation Pockets
for Autographs
The Scientific bit:
1. PVC - Top Loaders & Sweating
2. Plasticizer - What's this?
3. Humidity - RH?
1. PVC
PVC Top-loaders seem to be the choice for autograph collectors and dealers because they offer rigid protection and prevent creases and folds.
This may well be true, however top loaders tend to "sweat" and stick to photos/autographs if left inside them over prolonged periods of time.
This "sweating" makes it difficult to remove the autograph from the top loader.
The "sweating" will even lift the signature from the photograph, therefore damaging your autograph and photos irreversibly. (The same is true for all PVC plastic wallets).
2. Plasticizer
This chemical is added to PVC.
What does it do?
It makes PVC supple and stops it from becoming rigid. However the effect of plasticizer on your photos and sharpie ink signatures can be catastrophic; especially sharpies using metallic Silver or Gold ink.
The plastisizer effect transfers the autograph to the inside of the Top loader or PVC wallet..!
Additionally PVC plastics generate acids which react with photographic chemicals. It is this reaction that can fade photographs.
Not to mention that Polyvinyl Chloride is present in certain types of plastic including PVC and can emit Hyrdrochloric Acids as it degrades causing damage to all materials stored within.
PVC is often recycled and can have "fatty acid slip coatings" to make it run smoother on the production machinery. This too is potentilly harmfull to both photos and sharpie ink signatures!
3. Humidity
Photographs are particularly sensitive to humidity.
A stable relative humidity (RH) should be sought to avoid fluctuations that can cause cracking of surface coatings.
Photographs generally require around 40% RH. If the RH exceeds 65% (and it fluctuates) condensation will form which will stick the photographic surface to the Top loader.
Our Library & Populi Boxes offer an integrated temperature and humidity "room within a room" system!
In short the fatty slip coatings, condensation as well as plasticizer, will all affect the chemicals on the photo and sharpie ink , which in turn will cause image and signature transfer from the photo onto the plastic wallet or Top-loader.
The Solution
So is there an alternative to PVC?
YES! - POLYESTER
Polyester is known as the most Stable and Chemically Inert material used for conservation storage today!
Polyester has a higher melting temperature
(250-265C) than softer plastics such as Polyethylene and Polypropylene!
Polyester is fungus resistant and has a higher tear strength than any other plastic film.
Polyester pockets are renowned for their superb optical clarity, quality and reliability and are beautiful
to touch.
Polyester pockets contain NO plasticizer and are surface free of slip coatings. They are particularly suitable for letters, photographs and autographs!
Our polyester pockets give full archival protection against physical damage, surface reaction and atmospheric contamination!
Our polyester pockets offer excellent transparency and are particularly well suited for protecting documents and photos where transparency is required for viewing.
In fact our NEW Polyester pockets are made from 100% pure uncoated Polyester which offers unparelleled CRYSTAL CLEAR optical quality !
Their smooth surface allows removal and insertion
of documents, photos or ephimera with no risk
of abrasion.
Our polyester pockets have considerable physical strength and offer good mechanical resistance against folding, tears and friction.
They fit both the Library & Populi ringbinder boxes,
open on the short side of the page and pass the
We recommend around 50 pockets per storage box and ONE autograph per pocket only.
Why can't I put more photos in a single pocket?
One photo per pocket is advisable.
Photo paper with time will slowly degrate and in the process it will release gases.
It is the fine balance between the speed by which the gases released by the photo exit the polyester pocket and the speed by which oxygen enters the pocket that can determine how fast your photo will turn yellow.
Too fast too soon and your photo will go yellow faster.
Our polyester pockets have a lip at the top which acts as a valve regulating the speed of the whole process.
Placing two or more photos in the same pocket will not only double the lignin and acid present in the pocket but will also double (or triple) the amount of gases present in the pocket.
Needless to say your photos will turn yellow twice as fast which basically defeats the whole idea of conservation.
In short our polyester pockets are inert to anything placed in them and these pockets will preserve your autographs and photos indefinitely and safely!
Additionally, your autographs, photos, COA's & loose documents can be Professionally Organised, Displayed and Browsed within the perfect safety of our polyester pockets by using
our Archival
A number of customers have been asking us about other brand name products they have occasionally used.Well, if you already using pockets other than PVC chances are they are "polypropylene" pockets?
This material is used due to its characteristics ie: low melt temperature which allows to create multiple pockets within a single page cheaply.
If you are using any other pocket than POLYESTER you should look into whether they pass the
Photographic Activity Test (PAT) and whether they are Plasticizer Free.
In our experience they fall at the first hurdle.
I would also question their chemical stability, as there are different grades of polypropylene. Our products are very particular and only HIGH GRADE VIRGIN POLYPROPYLENE is used.
Polypropylene doesn't necessarily mean bad news, but we know the grade, purity and the application the products were designed and tested for.
Our Polyester pockets are made from a unique high grade polyester and polyethylene laminate. The films are Non migratory meaning they are chemically stable and there will be no leaching from the pockets to the photographs stored in them.
