diff --git a/Cargo.lock b/Cargo.lock
index e2c0ecf..a9d8eac 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -123,6 +123,7 @@ dependencies = [
  "futures",
  "lazy_static",
  "num_cpus",
+ "once_cell",
  "pin-project",
  "serde",
  "serde_cbor",
diff --git a/Cargo.toml b/Cargo.toml
index da9653a..c117705 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -24,6 +24,7 @@ color-eyre = {version = "0.5.10", default-features=false}
 futures = "0.3.12"
 lazy_static = "1.4.0"
 num_cpus = "1.13.0"
+once_cell = "1.5.2"
 pin-project = "1.0.5"
 serde = {version = "1.0.123", features=["derive"], optional=true}
 serde_cbor = {version = "0.11.1", optional=true}
diff --git a/src/arg.rs b/src/arg.rs
index 0eab1d7..715cfed 100644
--- a/src/arg.rs
+++ b/src/arg.rs
@@ -39,6 +39,8 @@ OPTIONS:
  -M			Set number of parallel running tasks to unlimited. (Same as `--threads 0`). (default).
  -m			Limit number of parallel tasks to the number of active CPU processors.
  -q			Quiet mode. Don't output info messages about successful `stat`ing.
+ -Q			Silent mode. Don't output any messages.
+ -v			Verbose mode. Output extra information.
  --save <file>		Dump the collected data to this file for further inspection (only available when compiled with feature `inspect`)
  -D			Dump the collected data to `stdout` (see `--save`) (only available when compiled with feature `inspect`)
  -			Stop parsing arguments, treat all the rest as paths. 
@@ -104,7 +106,13 @@ fn parse<I: IntoIterator<Item=String>>(args: I) -> eyre::Result<Mode>
 		    cfg.max_tasks = config::max_tasks_cpus();
 		},
 		"-q" => {
-		    cfg.silent = true;
+		    cfg.output_level = config::OutputLevel::Quiet;
+		},
+		"-Q" => {
+		    cfg.output_level = config::OutputLevel::Silent;
+		},
+		"-v" => {
+		    cfg.output_level = config::OutputLevel::Verbose;
 		},
 		#[cfg(feature="inspect")] "-D" => {
 		    cfg.serialise_output = Some(None);
diff --git a/src/config.rs b/src/config.rs
index 5e66e6c..42bc62b 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -1,6 +1,57 @@
 use std::path::PathBuf;
 use std::num::NonZeroUsize;
 use std::{fmt,error};
+use once_cell::sync::OnceCell;
+
+static GLOBAL: OnceCell<Config> = OnceCell::new();
+
+/// Get the global config instance, if it has been set.
+#[inline] pub fn try_get_global() -> Option<&'static Config>
+{
+    GLOBAL.get()
+}
+
+/// Get the global config instance.
+/// # Panics
+/// If one has not been set yet.
+pub fn get_global() -> &'static Config
+{
+    try_get_global().expect("Tried to access global config when it had not been initialised")
+}
+
+/// Try to set the global config instance, if it hasn't been already.
+#[inline] pub fn try_set_global(cfg: Config) -> Result<(), Config>
+{
+    GLOBAL.set(cfg)
+}
+
+/// Set the global config instance.
+/// # Panics
+/// If one has already been set.
+pub fn set_global(cfg: Config)
+{
+    try_set_global(cfg).expect("Tried to set global config more than once")
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Copy, PartialOrd, Ord)]
+#[repr(u32)]
+pub enum OutputLevel
+{
+    Silent = 0,
+    Quiet = 1,
+    Noisy = 2,
+    Verbose = 3,
+}
+
+impl Default for OutputLevel
+{
+    #[inline]
+    fn default() -> Self
+    {
+	Self::Noisy
+    }
+}
+
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum Recursion
@@ -54,7 +105,7 @@ pub struct Config
     pub recursive: Recursion,
     pub max_tasks: Option<NonZeroUsize>,
 
-    pub silent: bool,
+    pub output_level: OutputLevel,
     
     #[cfg(feature="inspect")]
     pub serialise_output: Option<Option<PathBuf>>, // Some(None) means dump to `stdout`
@@ -62,6 +113,20 @@ pub struct Config
 
 impl Config
 {
+    /// Try to make this the global config instance, if one does not already exist.
+    #[inline] pub fn try_make_global(self) -> Result<&'static Self, Self>
+    {
+	try_set_global(self).map(|_| get_global())
+    }
+    /// Make this the global config instance.
+    /// # Panics
+    /// If a global config instance has already been set.
+    #[inline] pub fn make_global(self) -> &'static Self
+    {
+	set_global(self);
+	get_global()
+	//GLOBAL.get_or_init(move || self) // This isn't okay to do here. As it would silently fail if there was already an instance, when we want it to panic in that case.
+    }
     /// Are we expected to dump data to `stdout`?
     #[inline] pub fn is_using_stdout(&self) -> bool
     {
@@ -96,7 +161,7 @@ impl Default for Config
 	    paths: Vec::new(),
 	    recursive: Default::default(),
 	    max_tasks: None, //max_tasks_cpus(),
-	    silent: false,
+	    output_level: Default::default(),
 	    #[cfg(feature="inspect")]
 	    serialise_output: None,
 	}
@@ -149,11 +214,19 @@ impl fmt::Display for InvalidConfigError
     }
 }
 
+
 /// Print an error line in accordance with `Config`'s output directives.
 #[macro_export] macro_rules! cfg_eprintln {
     ($cfg:expr, $fmt:literal $($tt:tt)*) => {
 	{
-	    if !$cfg.silent {
+	    if $cfg.output_level > $crate::config::OutputLevel::Silent {
+		eprintln!($fmt $($tt)*);
+	    }
+	}
+    };
+    ($level:ident; $cfg:expr, $fmt:literal $($tt:tt)*) => {
+	{
+	    if $cfg.output_level >= $crate::config::OutputLevel::$level {
 		eprintln!($fmt $($tt)*);
 	    }
 	}
@@ -165,7 +238,7 @@ impl fmt::Display for InvalidConfigError
     ($cfg:expr, $fmt:literal $($tt:tt)*) => {
 	{
 	    let cfg = &$cfg;
-	    if !cfg.silent {
+	    if cfg.output_level > $crate::config::OutputLevel::Quiet {
 		if cfg.is_using_stdout() {
 		    eprintln!($fmt $($tt)*);
 		} else {
@@ -173,5 +246,18 @@ impl fmt::Display for InvalidConfigError
 		}
 	    }
 	}
-    }
+    };
+    ($level:ident; $cfg:expr, $fmt:literal $($tt:tt)*) => {
+	{
+	    let cfg = &$cfg;
+	    if cfg.output_level >= $crate::config::OutputLevel::$level {
+		if cfg.is_using_stdout() {
+		    eprintln!($fmt $($tt)*);
+		} else {
+		    println!($fmt $($tt)*);
+		}
+	    }
+	}
+    };
+    
 }
diff --git a/src/defer_drop.rs b/src/defer_drop.rs
index ed46f5a..56dd685 100644
--- a/src/defer_drop.rs
+++ b/src/defer_drop.rs
@@ -1,4 +1,5 @@
 //! Mechanism to defer dropping of large objects to background threads
+use super::*;
 use futures::{
     prelude::*,
     future::OptionFuture,
@@ -16,7 +17,7 @@ where T: Send + 'static
 {
     let len_bytes = vec.len() * std::mem::size_of::<T>();
     OptionFuture::from(if len_bytes >  DEFER_DROP_VEC_SIZE_FLOOR {
-	eprintln!("Size of vector ({} bytes, {} elements of {:?}) exceeds defer drop size floor {}. Moving vector to a seperate thread for de-allocation", len_bytes, vec.len(), std::any::type_name::<T>(), DEFER_DROP_VEC_SIZE_FLOOR);
+	cfg_eprintln!(Verbose; config::get_global(), "Size of vector ({} bytes, {} elements of {:?}) exceeds defer drop size floor {}. Moving vector to a seperate thread for de-allocation", len_bytes, vec.len(), std::any::type_name::<T>(), DEFER_DROP_VEC_SIZE_FLOOR);
 	Some(async move {
 	    tokio::task::spawn_blocking(move || drop(vec)).await.expect("Child panic while dropping vector");
 	})
@@ -33,7 +34,7 @@ where T: Send + 'static
 {
     let len_bytes = vec.len() * std::mem::size_of::<T>();
     if len_bytes >  DEFER_DROP_VEC_SIZE_FLOOR {
-	eprintln!("Size of vector ({} bytes, {} elements of {:?}) exceeds defer drop size floor {}. Moving vector to a seperate thread for de-allocation", len_bytes, vec.len(), std::any::type_name::<T>(), DEFER_DROP_VEC_SIZE_FLOOR);
+	cfg_eprintln!(Verbose; config::get_global(), "Size of vector ({} bytes, {} elements of {:?}) exceeds defer drop size floor {}. Moving vector to a seperate thread for de-allocation", len_bytes, vec.len(), std::any::type_name::<T>(), DEFER_DROP_VEC_SIZE_FLOOR);
 	tokio::task::spawn_blocking(move || drop(vec));
     }
 }
diff --git a/src/main.rs b/src/main.rs
index 9becbe9..c9b59dc 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -42,23 +42,22 @@ async fn normal(cfg: config::Config) -> eyre::Result<()>
 	    return Err(eyre!("Interrupt signalled, exiting"));
 	}
     };
+    
+    let cfg = cfg.make_global();
     let graph = tokio::task::spawn_blocking(move || {
+	cfg_println!(Verbose; cfg, "Computing hierarchy...");
 	let mut graph = graph.into_hierarchical();
+	cfg_println!(Verbose; cfg, "Computing sizes...");
+
 	graph.compute_recursive_sizes();
 	graph
     }).await.expect("Failed to compute hierarchy from graph");
 
-    #[cfg(debug_assertions)] eprintln!("{:?}", graph);
+    #[cfg(debug_assertions)] cfg_eprintln!(Verbose; cfg, "{:?}", graph);
     
-    if cfg.is_using_stdout() {
-	eprintln!("Max size file: {:?}", graph.path_max_size_for(data::FsKind::File));
-	eprintln!("Max size dir: {:?}", graph.path_max_size_for(data::FsKind::Directory));
-	eprintln!("Max size all: {:?}", graph.path_max_size());
-    } else {
-	println!("Max size file: {:?}", graph.path_max_size_for(data::FsKind::File));
-	println!("Max size dir: {:?}", graph.path_max_size_for(data::FsKind::Directory));
-	println!("Max size all: {:?}", graph.path_max_size());
-    }
+    cfg_println!(Quiet; cfg, "Max size file: {:?}", graph.path_max_size_for(data::FsKind::File));
+    cfg_println!(Quiet; cfg, "Max size dir: {:?}", graph.path_max_size_for(data::FsKind::Directory));
+    cfg_println!(Quiet; cfg, "Max size all: {:?}", graph.path_max_size());
 
     #[cfg(feature="inspect")]
     match cfg.serialise_output.as_ref().map(|ser_out| {
diff --git a/src/serial.rs b/src/serial.rs
index 645653d..891c084 100644
--- a/src/serial.rs
+++ b/src/serial.rs
@@ -27,7 +27,7 @@ where W: AsyncWrite + Unpin
     {
 	let mut stream = Compressor::new(&mut to);
 
-	eprintln!("Writing {} bytes of type {:?} to stream of type {:?}", vec.len(), std::any::type_name::<T>(), std::any::type_name::<W>());
+	cfg_eprintln!(Verbose; config::get_global(), "Writing {} bytes of type {:?} to stream of type {:?}", vec.len(), std::any::type_name::<T>(), std::any::type_name::<W>());
 
 	stream.write_all(&vec[..])
 	    .await
diff --git a/src/work.rs b/src/work.rs
index b95a615..6b06ee1 100644
--- a/src/work.rs
+++ b/src/work.rs
@@ -47,7 +47,7 @@ pub async fn work_on_all(state: State) -> (INodeInfoGraph, Config)
 			.ok()
 		},
 		Err(err) => {
-		    eprintln!("Failed to stat root {:?}: {}", path, err);
+		    cfg_eprintln!(state.config(), "Failed to stat root {:?}: {}", path, err);
 		    None
 		},
 	    }
@@ -117,15 +117,15 @@ fn walk(state: State, root: PathBuf, root_ino: INode) -> BoxFuture<'static, Hash
 					    let mut cache = state.cache_sub();
 					    cache.insert(ino, fsinfo).await;
         				},
-					Err(err) => eprintln!("Failed to stat {:?}: {}", entry.path(), err),
+					Err(err) => cfg_eprintln!(state.config(), "Failed to stat {:?}: {}", entry.path(), err),
 				    }
 				}
 			    },
-			    Err(err) => eprintln!("Walking {:?} failed: {}", root, err),
+			    Err(err) => cfg_eprintln!(state.config(), "Walking {:?} failed: {}", root, err),
 			}
 		    }
 		},
-		Err(err) => eprintln!("Failed to walk {:?}: {}", root, err),
+		Err(err) => cfg_eprintln!(state.config(), "Failed to walk {:?}: {}", root, err),
 	    }
 	    // drop work guard here
 	}
@@ -136,7 +136,7 @@ fn walk(state: State, root: PathBuf, root_ino: INode) -> BoxFuture<'static, Hash
 	    {
 		output.extend(map);
 	    } else {
-		eprintln!("Child panic");
+		cfg_eprintln!(state.config(), "Child panic");
 	    }
 	}