How to set seattle.master page or How to remove custom master page from library pages like editForm.aspx,newForm.aspx,etc. in SharePoint Foundation 2013?

Hi,

I have created a custom master page and applied to entire site collection.

But when I add new item in document library while adding metadata information it shows custom master page content also.

However I don't want to show custom master page content in NewForm.aspx page of Document Library.

I have SharePoint 2013 Foundation version.

Can anybody help me to set seattle.master page to system pages.

Chaitanya