Your custom, personalised and individually handmade order will be ready for delivery in 3 - 4 weeks.

Your Cart is Empty

Shop For
  • Help & Information
  • Gallery

  • Portfolio book inside portfolio box

    Portfolio books and boxes used by professional Photographers, Designers and Architects


  • leather tender presentation proposal box and binder

    Presentation binders and boxes made by us and used by Companies and Corporations


  • Bespoke leather guest book

    Products used in Restaurants, Boutique Hotels and on Super Yachts


  • thumbnail custom vehicle history binder

    Bespoke binders and boxes for classic cars and motorcycles

  • Ring Binder and Lever Arch Mechanism Guide

    Ring binder and lever arch mechanisms available for hartnack and co portfolios

    What Binder Sizes Are Available?

    The largest mechanism, on the far left hand side of the picture, has a 12cm capacity, the smallest on the right has a 2.5cm capacity. To put this in more meaningful context, the lever arch mechanism in the middle (which is a standard lever arch mechanism) has a 4.5mm capacity.

    What Do You Mean By Capacity?

    How much the binder can take measured in centimetres. The size of the binder (eg, 4cm) doesn't refer to the physical height of the mechanism but the gap between the top of the plate and the vertical length of the binder before it starts to curve round at the top.

    We refer to each mechanism by size and type, for example a '4cm D Ring Binder'. This gives you an idea, when ordering, which size binder mechanism you need depending upon the volume being put in the binder.

    ring binder capacity

    How Do I Know What Size Binder I Will Need?

    This can depend on whether the contents of your portfolio are in page protectors, or, have 1 or 2 pages in each page protector. Also the quality (thickness) of the page protector material or the pages themselves.

    As an 'approximation' the 6.5cm mechanism will hold (comfortably) 150 page protectors.

    Without wanting to sound deliberately patronising, the only way to figure it out accurately, is to pile up the contents and measure it.

    what size ring binder do i need for my portfolio?

    What Binder Mechanisms Are Available?

    'O' Ring Binder

    'D' Ring Binder

    'Q' Ring Binder

    Super Binder (Discontinued & no longer available)

    Lever Arch Binder 

    Traditional lever arch binder mechanisms available in chrome only and comes with a tensioner bar :

    3.5 cm- to order
    5.5 cm- ex stock
    6.5 cm- ex stock

    The capacity sizes are measured up to the bend underneath the opening.

    medium and large lever arch file mechanism

    Black Binder Mechanisms

    Currently the only mechanisms that are available in black are the 4cm and 5cm D Ring. We have discontinued the black 2.5cm mechanism but should this change, we will update it here.

    What Style of Portfolio Can Have a Ring Binder or Lever Arch Mechanism?

    Custom Ring Binder Portfolios, the full leather portfolio and the clam shell boxes, can have any binder mechanism placed in them. 

    How Strong Are They?

    As a manufacturer of premium bespoke portfolios and binders we have endeavoured to source what we believe are the finest mechanisms on the market. The brand is Benson which have now been amalgamated into Ring Alliance.

    Ring Alliance's website can be found here. If there is a particular size you would like, please have a look at their website and ask us to quote based on their reference.

    Can You Make Custom U.S. 3 Ring Binders?

    In a single word, Yes. As you can see from the photo at the top of the page, our stock of 3 ring mechanisms is limited to the size we get asked for the most, but our supplier has a large range of 3 ring mechanisms, so ask and we will get it for you. Their American 3 ring pages can be found here for D ring and here for O ring.

    Ordering a custom made ring binder can be done here on our ring binders collection page