( Note 15 may 2019:  Update of the EEVEE shaders due to changes in Blender. Update to the latest Blender build. ) 

In Short: 

Let me guess. you  have a shader library but sometimes a yellow plastic shader looks more like a light, wood like snow or sometimes like a texture with to much contrast.  And you noticed some weird pixelation artefact in EEVEE when using bump-maps.  Probably there is a reason you are here. 

In EEVEE the bump maps show up pixelated and therefore we better use normal maps.  Normal maps process faster as well.  This packages provides 260 normal maps and 260 masks.  The masks can be used to define anything from roughness to albedo. We can also mix normal maps with it.  

There are 4 kind of shaders provided: Level 1, 2, 3 and Advanced and 40 example shaders.  You can use your own shaders or use the add-on BATS as well.

The shaders are designed in a Neutral Environment and calibration is done with False Color and a grey-card.  A scene with the neutral environment and the grey-card is also provided.  (See links to video in documentation.)

So what is in the package:  

• 260 Normal maps.  (2K Jpg)
• 260 Masks               (2K Jpg)
• 40 Shaders as example 
• 4 shader types. (L1, L2, L3, Adv).  
• Albedo/greycard
• Neutral Environment, a scene in EEVEE.  
• Extra Blendfile to mix normal maps
• Extra Blendfile to bake normal maps from geometrie
• Thumbnails of the shaders.  
• Pixaflux project files (some of the normal maps are designed with pixaflux).

Above is packed in a .zip file of 356Mb.  Once Unzipped it will be 707Mb. Unzip it in a location you prefer but don't change the internal map structure because the blendfiles use relative path to the textures and masks.   

Useful tools/addons:

• The normal maps and masks can also be used with BATS which is an excellent addon to make materials.  
• Simple Asset Manager is useful to easily import materials into Blender 2.80
• There are several addons to bake materials. See for an extensive list of addons for Blender 2.80 this thread.   
• With PixaFlux you can design Normal maps and masks yourself.  There are some PixaFlux project files included.  (For the noise patterns only). 

License

That is the boring part.  You cannot sell or distribute directly this package as is.   But if you have a nice scene and had quite some effort, it's ok to me if you use some of the materials. Or be free to bake the textures otherwise if you use them extensively. The point is I don't want anyone else to sell this package without some effort.  (Just buying and reselling).  If you have questions, contact me.  

Update 15 May 2019: 

Update due to changes in the latest Blender build.  (See developers notes:  Image textures now use the color space on the image datablock instead of the node, and use OpenColorIO for conversion. Eevee and workbench now match Cycles handling of colorspace and alpha handling more closely. ) 
IUse the latest Blender Build. 

Additionally added free 3 party normap maps so you don't have collect and download these yourself.  Thanks to 3D Textures and Texture Heaven  

The zip-file is 721Mb and unpacked 1.06Gb.