I keep mine (a) under the carpet, during the winter, in a spare bedroom; this flattens them out and (b) under the double bunk on the boat, during the summer, with just ready use ones at the chart table.
Hm, i think this is far too big and complicated a subject to be covered here. You should consider getting some training, really.
Don't leap in at the deep end - start with easy things like "An introduction to things made of paper" which will show various ways in which paper can get a bit crumpled, and how some things are made of thick paper and other things are thinner paper.
From there, it should be sensible to progress to "Paper in the Marine Environment" which will explain how paper gets a bit fluttery in the wind, and how important it is not to get it wet.
Finally, a course in "Special Problems with on-board Paper-based items" would be appropriate. This include a morning on choosing loo paper and selecting suitable storage place for it so it doesn't get soggy or weed on, a whole day on the importance of choosing paperback books that aren't too big to fit in a bookshelf (a very common mistake) and finally a two-day practical on rolling, unrolling and re-re-rolling charts so they stay flat for the chart table, which i think will be the element of most interest to you.
If there's time, they can usually make a start on the principles of opening and refolding the folded charts, although really it requires fulltime study over three years.
I work with the Hydrographic side of the RN at the moment and we try not to roll charts up too much! I used to spend ages trying to roll them back against the way that they were rolled to 'unroll them'.
Bit of research... I have just spoken with the archivist to the UKHO who holds copies of every chart that has ever been published by the Admiralty and he says all his charts are flat and that as far as he knows they were only ever rolled for posting. Perhaps ships then kept them rolled subsequently? I also just asked the CO of one of our survey vessels. He said "we just unroll them, put them in the folio and they flatten out after a few days".
This only covers published charts and does not cover the 'private charts, personally annotated and collated' that sailing masters would take with them from vessel to vessel. (Sailing master arrives, sextant under one arm and his personal charts rolled under the other...)
I also have on my desk in front of me a leather covered "Chart Weight" one of several that would have been used to keep the things flat. There's another one holding the door open to the outer office...
I keep my own charts on our boat flat - usually storing the folios not in use under the pilot berth bunks.
One trick to flatten paper that is curled and crinkled is to iron it! Not sure that I'd recommend it for charts as they can go out of shape. (Note the bottom right corner of Admiralty Charts where the original dimensions of the paper are listed for those who are interested in high degrees of accuracy!)
Don't know if that helps, but you've now got some background information from one of the horses mouths...
We have all our charts turned into steel litho plates. If you take any paper or computer image to a litho printer they will make a metal printing plate from it. This is great because it can be written on over and over again and it will never curl or go soggy.
There was the unfortunate event last season when it blew out of my hands and the sharp metal edge decapitated the wife's Dachshund. Personally I think it was a small price to pay for the ease of use I get from this form of chart.
oh dear, what a small-minded response. Appropriate I suppose. It was lighthearted and harmless, although i liked pasta-simon's "deadpan" reponse even more. It's good that everyone normally resists making funnies on PBO but i made an exception for someone asking how to get a curly piece of paper to go flat . My small children were puzzled that anyone would need to ask such a simple question. You did actually get a fairly useful response, although I'm not alone in wondering what use you can make of a charts for if you even need help working out how to flatten them. Nuff said anyway...
Trick is unroll and then lay upside down ......... so they try toi tuck under instead of curling up. If you can - 'back-roll' the chart forcing it to rol up against the natural curl direction .... then let it lay flat upside down. A book or something in the middle will then after a few days / week or so cure it.
Imagine what we had with 2000 charts on ship !! But then we also had the canvas chart folio holders with small strip ties as well to force them flat .... maybe a variation on that .... large canvas folded and tied of ??
All charts that I received on Ship were rolled into chart tubes ............ no matter how many were sent out .... if I took direct from Chart Agents ... they were ex chart draws and flat .... its the forwarding toi ship that does it - the tubes !!
Hi....I s'pose it's another advantage of a catamaran, but I have a sizeable space on the bathroom wall...sorry, heads bulkhead....where I store maybe twenty full size charts flat behind a lattice of bungy cord. The current chart of interest faces outward and can be consulted in situ, or slid out onto the living-room...sorry, saloon table for "proper" navigation with rulers and pencils and stuff. Works well, the last twelve years, same old bungy cord. Same old charts too.
The problem is when you stack em up, unless you store them horizontally they tend to roll about a bit..
Anyway - didn't you know - you can get double sided CDs ....
And ... if you get a few CDs together you can put them on 1 DVD !! Amazing huh?!