diff --git a/NAPS2.Sdk/Scan/BitDepthCaps.cs b/NAPS2.Sdk/Scan/BitDepthCaps.cs
index e13066635d..bac91e853b 100644
--- a/NAPS2.Sdk/Scan/BitDepthCaps.cs
+++ b/NAPS2.Sdk/Scan/BitDepthCaps.cs
@@ -1,10 +1,22 @@
 namespace NAPS2.Scan;
 
+/// <summary>
+/// Represents valid values for ScanOptions.BitDepth as part of PerSourceCaps.
+/// </summary>
 public class BitDepthCaps
 {
+    /// <summary>
+    /// Whether the scanner supports BitDepth.Color.
+    /// </summary>
     public bool SupportsColor { get; init; }
 
+    /// <summary>
+    /// Whether the scanner supports BitDepth.Grayscale.
+    /// </summary>
     public bool SupportsGrayscale { get; init; }
 
+    /// <summary>
+    /// Whether the scanner supports BitDepth.BlackAndWhite.
+    /// </summary>
     public bool SupportsBlackAndWhite { get; init; }
 }
\ No newline at end of file
diff --git a/NAPS2.Sdk/Scan/DpiCaps.cs b/NAPS2.Sdk/Scan/DpiCaps.cs
index 48bad12055..c877d198a9 100644
--- a/NAPS2.Sdk/Scan/DpiCaps.cs
+++ b/NAPS2.Sdk/Scan/DpiCaps.cs
@@ -2,10 +2,20 @@
 
 namespace NAPS2.Scan;
 
+/// <summary>
+/// Represents valid values for ScanOptions.Dpi as part of PerSourceCaps.
+/// </summary>
 public class DpiCaps
 {
     private static readonly int[] TargetCommonValues = [0, 100, 150, 200, 300, 400, 600, 800, 1200, 2400, 4800];
 
+    /// <summary>
+    /// Creates an instance of DpiCaps that allows values in the specified range.
+    /// </summary>
+    /// <param name="min">The lowest valid DPI value, inclusive.</param>
+    /// <param name="max">The highest valid DPI value, inclusive.</param>
+    /// <param name="step">The increment between valid DPI values (must be >0).</param>
+    /// <returns></returns>
     public static DpiCaps ForRange(int min, int max, int step)
     {
         if (step <= 0) return new DpiCaps();
@@ -20,8 +30,14 @@ public static DpiCaps ForRange(int min, int max, int step)
         };
     }
 
+    /// <summary>
+    /// Allowed values for ScanOptions.Dpi.
+    /// </summary>
     public ImmutableList<int>? Values { get; init; }
 
+    /// <summary>
+    /// Recommended values for ScanOptions.Dpi to be presented to the user.
+    /// </summary>
     public ImmutableList<int>? CommonValues
     {
         get
diff --git a/NAPS2.Sdk/Scan/MetadataCaps.cs b/NAPS2.Sdk/Scan/MetadataCaps.cs
index 252a121f60..c02f59f275 100644
--- a/NAPS2.Sdk/Scan/MetadataCaps.cs
+++ b/NAPS2.Sdk/Scan/MetadataCaps.cs
@@ -1,16 +1,37 @@
 namespace NAPS2.Scan;
 
+/// <summary>
+/// Represents scanner metadata as part of ScanCaps.
+/// </summary>
 public class MetadataCaps
 {
+    /// <summary>
+    /// For SANE, this is the backend name.
+    /// </summary>
     public string? DriverSubtype { get; init; }
 
+    /// <summary>
+    /// The device manufacturer.
+    /// </summary>
     public string? Manufacturer { get; init; }
 
+    /// <summary>
+    /// The device model name.
+    /// </summary>
     public string? Model { get; init; }
 
+    /// <summary>
+    /// The device serial number.
+    /// </summary>
     public string? SerialNumber { get; init; }
 
+    /// <summary>
+    /// The location note associated with the device.
+    /// </summary>
     public string? Location { get; init; }
 
+    /// <summary>
+    /// The URI for an icon associated with the device.
+    /// </summary>
     public string? IconUri { get; init; }
 }
\ No newline at end of file
diff --git a/NAPS2.Sdk/Scan/PageSizeCaps.cs b/NAPS2.Sdk/Scan/PageSizeCaps.cs
index 838b1a9773..5b95777338 100644
--- a/NAPS2.Sdk/Scan/PageSizeCaps.cs
+++ b/NAPS2.Sdk/Scan/PageSizeCaps.cs
@@ -1,9 +1,18 @@
 namespace NAPS2.Scan;
 
+/// <summary>
+/// Represents valid values for ScanOptions.PageSize as part of PerSourceCaps.
+/// </summary>
 public class PageSizeCaps
 {
+    /// <summary>
+    /// Gets the size of the full scan area (i.e. maximum page size).
+    /// </summary>
     public PageSize? ScanArea { get; init; }
 
+    /// <summary>
+    /// Determines whether the provided page size fits within the full scan area (with 1% margin of error).
+    /// </summary>
     public bool Fits(PageSize pageSize)
     {
         if (ScanArea == null)
diff --git a/NAPS2.Sdk/Scan/PaperSourceCaps.cs b/NAPS2.Sdk/Scan/PaperSourceCaps.cs
index 2737a82a85..35acb28b47 100644
--- a/NAPS2.Sdk/Scan/PaperSourceCaps.cs
+++ b/NAPS2.Sdk/Scan/PaperSourceCaps.cs
@@ -1,12 +1,27 @@
 namespace NAPS2.Scan;
 
+/// <summary>
+/// Represents valid values for ScanOptions.PaperSource as part of ScanCaps.
+/// </summary>
 public class PaperSourceCaps
 {
+    /// <summary>
+    /// Whether the scanner supports PaperSource.Flatbed.
+    /// </summary>
     public bool SupportsFlatbed { get; init; }
 
+    /// <summary>
+    /// Whether the scanner supports PaperSource.Feeder.
+    /// </summary>
     public bool SupportsFeeder { get; init; }
 
+    /// <summary>
+    /// Whether the scanner supports PaperSource.Duplex.
+    /// </summary>
     public bool SupportsDuplex { get; init; }
 
+    /// <summary>
+    /// Whether the scanner has the ability to detect if paper is in the feeder for use with PaperSource.Auto.
+    /// </summary>
     public bool CanCheckIfFeederHasPaper { get; init; }
 }
\ No newline at end of file
diff --git a/NAPS2.Sdk/Scan/PerSourceCaps.cs b/NAPS2.Sdk/Scan/PerSourceCaps.cs
index ec2344dae6..f98e4a7e43 100644
--- a/NAPS2.Sdk/Scan/PerSourceCaps.cs
+++ b/NAPS2.Sdk/Scan/PerSourceCaps.cs
@@ -2,8 +2,15 @@
 
 namespace NAPS2.Scan;
 
+/// <summary>
+/// Represents capabilities specific to a single PaperSource as part of ScanCaps.
+/// </summary>
 public class PerSourceCaps
 {
+    /// <summary>
+    /// Gets an object representing the union of all possible option values allowed by the provided objects.
+    /// This can be helpful when presenting the user with a single set of possible options for multiple sources.
+    /// </summary>
     public static PerSourceCaps UnionAll(ICollection<PerSourceCaps> caps)
     {
         DpiCaps? dpiCaps = null;
@@ -45,9 +52,18 @@ public static PerSourceCaps UnionAll(ICollection<PerSourceCaps> caps)
         };
     }
 
+    /// <summary>
+    /// Valid values for ScanOptions.Dpi.
+    /// </summary>
     public DpiCaps? DpiCaps { get; init; }
 
+    /// <summary>
+    /// Valid values for ScanOptions.BitDepth.
+    /// </summary>
     public BitDepthCaps? BitDepthCaps { get; init; }
 
+    /// <summary>
+    /// Valid values for ScanOptions.PageSize.
+    /// </summary>
     public PageSizeCaps? PageSizeCaps { get; init; }
 }
\ No newline at end of file
diff --git a/NAPS2.Sdk/Scan/ScanCaps.cs b/NAPS2.Sdk/Scan/ScanCaps.cs
index 92fe6e5a65..5e5ab7c508 100644
--- a/NAPS2.Sdk/Scan/ScanCaps.cs
+++ b/NAPS2.Sdk/Scan/ScanCaps.cs
@@ -1,14 +1,33 @@
 namespace NAPS2.Scan;
 
+/// <summary>
+/// Represents scanner capabilities. This includes valid values for scanning options and extra metadata beyond just the
+/// device name and id.
+/// </summary>
 public class ScanCaps
 {
+    /// <summary>
+    /// Metadata for the device.
+    /// </summary>
     public MetadataCaps? MetadataCaps { get; init; }
 
+    /// <summary>
+    /// Valid values for ScanOptions.PaperSource.
+    /// </summary>
     public PaperSourceCaps? PaperSourceCaps { get; init; }
 
+    /// <summary>
+    /// Capabilities specific to the Flatbed paper source.
+    /// </summary>
     public PerSourceCaps? FlatbedCaps { get; init; }
 
+    /// <summary>
+    /// Capabilities specific to the Feeder paper source.
+    /// </summary>
     public PerSourceCaps? FeederCaps { get; init; }
 
+    /// <summary>
+    /// Capabilities specific to the Duplex paper source.
+    /// </summary>
     public PerSourceCaps? DuplexCaps { get; init; }
 }
\ No newline at end of file