Hello!
Is possibile import a master Page from another dorico’s project?
Or Is possibile modify a master page and set it how default master page for future project?
Because in every new project I must modify the master P
page for full score and parts, and it’s very waste of time.
Thank you very much!
It’s not yet possible, sorry. You need to save your project and use it for all new projects at the moment.
To elaborate on Dan’s response, in other programs you will be familiar with the idea of importing house styles or libraries into your project (and this will become possible in future versions of Dorico, too), but for the time being in Dorico you do it the other way around: do File > Save As to save the project that contains your wanted master pages under another name, then delete all the players and flows from it, then either write your music directly into this new file, or if it already exists in another project, do File > Import > Flows to import those flows into the project, where they will then assume your existing master pages.
Ok, thank you very much!!!
Hello sorry for resurrecting an old thread, I just had a quick question - is it possible to transfer page templates between projects now? This is the most up to date thread I could find, so sorry if this is already has been answered/not changed since 2018!
Yes, it is 
In Engrave mode you can export page templates (so first, master and eventual additional ones like title pages) and then import them in another project. It works but I find the way it is setup rather clumsy,
After import you would probably have rename the imported page as I think the name of the saved file is not linked to page template name. Next you have to replace the default pages with imported ones for each page type you have in your project.
The template method with imported flows described above still seems the most efficient.
If you have a Page Template Set pair you would like to use for all (or most of) your projects, @FredGUnn has found a way to configure those as your default set for Score and Parts. That’s what I have done, and I find it very convenient.