Company supplied data list, with customer additions
For the sake of the customer having a local copy and the supplier having the master copy you could have two tables...
Supplier's Master Copy
blueprints_master
~id ~ name ~ colour ~
~ 1 ~ chair   ~  pink    ~
~ 2 ~ table   ~  blue    ~

Customer Local Copy
blueprints_customer

~id&nbsp;~&nbsp;name&nbsp;~&nbsp;colour&nbsp;~&nbsp;blueprits_master_id&nbsp;~
~&nbsp;1&nbsp;~&nbsp;chair&nbsp;&nbsp;&nbsp;~hot pink~&nbsp;&nbsp;1&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;~
~&nbsp;2&nbsp;~&nbsp;desk&nbsp;&nbsp;&nbsp;~&nbsp;wood&nbsp;&nbsp;&nbsp;~&nbsp;&nbsp;&nbsp;null&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;~

Problems Solved

  A list of blue prints the customer can add, remove, and update
  A link (foreign key) between a customers blueprint and a master blueprint
  I think this is useful in case the customer want's to "change" one of the master blueprints. Internally the system will create a new entry in the _cusomter table rather then changing the _master table, but the customer will still feel like they are doing what they wanted
  A list of blueprints the supplier has absolute control over

Problems Remaining

  Syncing the _customer and _master tables.

unfortunately I do not have any proposed solution to the syncing problem nor can I reference to any other post...