Remodel Blueprint

Blueprints are items used for remodeling certain ships, usually under the rationale of these ships' unique circumstances in history.

In addition to the difficulty of obtaining blueprints, ships that are upgraded in this manner tend to carry very rare and powerful stock equipment, making prioritizing certain remodels important.

How to Obtain

The only way to obtain a blueprint is by exchanging four medals, found in your inventory (the fourth panel from the left in the overhead menu). The following are ways to obtain medals:

Extra Operations

There are currently five extra operations in the game, accessible in World 1, World 2, World 3, World 4, and World 5. Clearing an extra operation yields one medal in addition to bountiful HQ experience; take note, however, that clearing 1-6 does not yield a medal, and instead rewards a present box.

The boss's health gauge will reset on the first of each month for each operation.
Extra Operations are intended to be significantly more challenging than other sorties in their respective worlds; sortieing to 2-5 immediately after clearing 2-4 is not recommended for this reason. 5-5's outstanding difficulty and potential ship requirements limit most players from clearing it.
This is the only consistent way to obtain medals.

Events

Medals are often rewarded in event maps, usually in the later stages. This isn't a reliable way to obtain them, but veteran players can acquire an additional blueprint during the event's duration through these medals.

The 2015 Winter and Spring events each yielded 5 medals for clearing all the maps on Hard; expect future events to follow a similar trend.

Other

Some quests also reward medals.

(List to be updated here)

Blueprint Requirements

The following ships require a blueprint for one or more of their remodels:

Abukuma
Amagi
Arashio
Bismarck (Fully remodeling her to Drei requires two blueprints)
Chikuma
Choukai
Fusou
Italia
Katsuragi
Kinu
Kumano (Requires a second blueprint each time she is remodelled into her reversible CVL form, but not vice versa)
Nagato
Ooshio
Roma
Ryuuhou
Saratoga (Also requires a Prototype Catapult)
Shoukaku (Also requires a Prototype Catapult)
Suzuya (Requires a second blueprint each time she is remodelled into her reversible CVL form, but not vice versa)
Taiyou (Also requires a Prototype Catapult)
Tone
Unryuu
Yamashiro
Yura
Zara
Zuikaku (Also requires a Prototype Catapult)

The total number of blueprints required for all of these remodels is 28. That in turn requires 112 medals!

Advice Regarding Blueprints

It is important to exercise Blueprint discipline, especially early on into the game and before events.

If you are unsure which ship to Blueprint, there is no harm in waiting for more information (especially during events) before committing to blueprinting a ship.

Failure to do so may affect your ability to clear an event, given how difficult it is early on to acquire enough medals for conversion into a Blueprint.