@eclku0 said in Encryption of a MicroSD card neccessary?:
Since the device is mounted inside of phablet, doesn't that mean that everything I write to it is encrypted?
To start with your last question. No. Even if you would mount your SD card under the phablet home directory, it would still be unencrypted.
What filesystem did you format your SD card with? There is a files size limit to the FAT32 filesystem.
But since you intend to mount an image file with an encrypted filesystem anyhow, you might want to format your SD card as ext4.