In response to personal need or requests by others, some AFOLs have created custom elements compatible with LEGO products. Unlike clone brands these are produced to fill a perceived gap rather than replace or compete with an existing element. Custom elements may be based on previous customized parts that have been successfully reproduced for sale to other AFOLs.
Custom elements should not be confused with decals which are applied to elements to create clothing, facial features or other decorative function.
One of the first to produce and market such elements was Ben Fleskes of Big Ben Bricks who designed train wheels that would more accurately represent real train wheels. Manufacturers such Fleskes and Will Chapman of BrickArms have proven that third-party accessories do not have to be inferior in quality.