When taking an Esri vector tiled basemap service offline (e.g. to create a VectorTileCache on your device), you can choose from different versions of the service depending on your use case.
Primary considerations are the download speed and the size of the resulting
.vtpk file. Among other things, file size is influenced by the amount of fonts downloaded from the service. Esri vector tiled basemap layers make use of fonts as part of their style resources - see the vector-tile-style documentation. When you take a vector tiled layer offline, these fonts are downloaded as part of the VectorTileCache.
Esri services also offer an alternative version with a reduced font package size which will reduce the download size of a vtpk by around
80 Mb. You can view a set of vector tile styles which use the reduced font services here. If you are creating a web map that is only intended for taking maps offline and not for online-viewing, these "for export" versions of the services are recommended.
This enumeration describes options for controlling which set of fonts are downloaded. Note that these options only apply to Esri vector tile basemap services.
The EsriVectorTilesDownloadOption can be one of:
(0) The complete set of vector tile resources for the original service, including the full set of fonts, will be downloaded. Downloading all font resources increases the download size of a .vtpk. However, this option ensures that the offline vector tile layer displays the same as the original online service.
(1) An alternative service that uses a reduced set of font resources, supporting a limited set of language characters, will be downloaded. Downloading the smaller set of font resources reduces the download size of a .vtpk by around
80 Mb. This omits the large Arial Unicode font that is used to support many characters for the full world basemap. This makes this option unsuitable for some locales or when your offline vector tiled layer includes certain character sets. For example, this option will not display Chinese, Japanese, Thai, Korean or Georgian characters. You should confirm that this option is suitable for your specific use-case.
You can view a set of vector tile styles which use the reduced font services here. This option is not recommended for Esri basemap services that do not have an equivalent "for export" version.