I got some more of the A5 file folders from Poundland here in the UK for various sized envelopes and also for 6x6 and A5 papers. I can confirm that 6x6 papers fit, with wiggle room. But again I have ladled these folders and filled up the rest of my tub. I even have 8/20 folders left for additional papers I buy. I also bought (on Ebay) some 12x12 papers and then from the Poundland I bought a pack of 2 A3 file folders but when these papers arrived they were sent in at 12x12 box ... I didn't realise these boxes existed!! So I’ll try and get some more if/when I buy some more 12x12 papers that aren’t monochrome (black and white).