Double coins storage

Hi all!

I have been collecting euro coins (mostly commemoratives but some standards as well) for a while now. My collection has grown quite a bit, and so have the double coins that I keep for swaps. 

A couple of years ago I purchased some plastic (PVC) loose album pages to keep my doubles organized and easily accessible, like these:

I was pretty satisfied with the result, because everything was properly sorted out and the loose pages let me arrange my coins as I wanted.

But then I got to know the harm that PVC does to coins, so I proceeded to take all my coins off the album pages and clean them from the sticky patina that the PVC was starting to form (especially on the ones that got placed on the album two years ago) with the help of acetone. It has been a dreadful process (circa 400 coins soaked and cleaned with cotton swabs one by one), but now I'm finished and I am looking for a new storage method for my coins. Right now I am storing them in cardboard boxes.

I would like to be able to see the coins at first glance so that I browse through them better, but I can't find loose album pages made of something else than PVC. Do such pages even exist?

I store my collection (not the doubles) in cardboard flips organized in album pages (PVC, but as long as my coins are in the flips it shouldn't be harmful), like this:

But I find it excessive (and expensive) to me to use flips for ALL of my doubles.

How could I store my coins? Can anyone suggest me something, maybe based on your experience?

Thank you a lot :)

I have my doubles in this kind of 2x2 envelopes

https://www.amazon.com/dp/B004WTYJ16?psc=1&ref=ppx_pop_dt_b_asin_image

Then you organize the envelopes as you like afterward and in the medium you have chosen (box, 2x2 page, drawer or what have you)

I put my 2x2 sheets into boxes with 50 sheets in each, so each box contains 50x20 = 1000 coins. I write e sequential number on each page before putting it into the box. Box 1 contains the sheets from 1 to 50, box 2 51 to 100 and so on.

In my doubles list I have a field (yellow) for the number of sheet containing the coin:

The big thing is, I use a buffer box where I have my latest 60 doubles coins in the location “Plast000”, so when I take a coin out of a sheet, I take one from plast000 and inserts it in the sheet I took the swapped double from. I then write the sheet number on the 2x2 envelope and change the plast000 in my doubles list to the new sheet number. It works very well.

I have 490 sheets with (10 boxes in two piles)) doubles for the moment. The only problem is of course the boxes, when I make a swap, I have to take them all out of my storage and since they are heavy, that's a bother, when getting old. But it's much easier than having the coins loose in envelopes!