Some binders come with plain flyleaves (like Gillio), whereas others, like Filofax, used to offer zipped flyleaves but don’t any more. Van Der Spek can make flyleaves in different colours – to match or contrast the colour of your binder. You can even buy a couple to ring the changes now and then.
Here is my custom flyleaf in Janet Leather. It has a secretarial pocket on one side and a zipper on the other. This is one they have not made before and which is quite difficult to do so will cost more than the ones above. But I want to use the zipper for coin money and the flap for paper money.
If you are interested in seeing the other custom options for your binder, click on this link. You can order extra pen loops, ring protectors and embossing.