macros - Kentico8 - New boolean field in existing page type, default value not set -

on our website want add "print" button on pages. goal add boolean field page type let's choose if want button on page or not.

this works fine little code in 'visible' checkbox of webpart containing print button:

{% currentdocument["printbutton"]#%} 

my problem this:

pages of type that exist automatically print button, tho field default value set 'no'

if check pages in 'pages' application, checkbox unchecked. when save , submit pages again, print button gone. but, might guess, don't want resubmit hundreds of pages...

it looks pages exist have no value in new boolean field, , therefor automatically resolve visible.

anyone clue how solve this?

when added field should have marked field required , set default value true. default have set fields true. next, if don't want have default value of true, go in , set false, subsequent pages added false default unless checks true.

another way set these run simple query against custom page type's table , set value. if have workflow and/or versioning enabled, gets little tricky not first route i'd take it's option.