diff --git a/SabreTools.DatTools/Rebuilder.cs b/SabreTools.DatTools/Rebuilder.cs
index cc61a328..64df84b0 100644
--- a/SabreTools.DatTools/Rebuilder.cs
+++ b/SabreTools.DatTools/Rebuilder.cs
@@ -470,7 +470,7 @@ namespace SabreTools.DatTools
                         outputFormat = OutputFormat.ParentFolder;
 
                     // Get the output archive, if possible
-                    Folder? outputArchive = GetPreconfiguredFolder(datFile, date, outputFormat);
+                    IFolder? outputArchive = GetPreconfiguredFolder(datFile, date, outputFormat);
 
                     // Now rebuild to the output file
                     outputArchive!.Write(fileStream, outDir, (item as Rom)!.ConvertToBaseFile());
@@ -516,7 +516,7 @@ namespace SabreTools.DatTools
                                 datItem.SetName($"{datItem.GetName()}_{crc}");
 
                                 // Get the output archive, if possible
-                                Folder? outputArchive = GetPreconfiguredFolder(datFile, date, outputFormat);
+                                IFolder? outputArchive = GetPreconfiguredFolder(datFile, date, outputFormat);
 
                                 // Now rebuild to the output file
                                 bool eitherSuccess = false;
@@ -822,9 +822,9 @@ namespace SabreTools.DatTools
         /// <param name="date">True if the date from the DAT should be used if available, false otherwise</param>
         /// <param name="outputFormat">Output format that files should be written to</param>
         /// <returns>Folder configured with proper flags</returns>
-        private static Folder? GetPreconfiguredFolder(DatFile datFile, bool date, OutputFormat outputFormat)
+        private static IFolder? GetPreconfiguredFolder(DatFile datFile, bool date, OutputFormat outputFormat)
         {
-            Folder? outputArchive = FileTypeTool.CreateFolderType(outputFormat);
+            IFolder? outputArchive = FileTypeTool.CreateFolderType(outputFormat);
             if (outputArchive is BaseArchive baseArchive && date)
                 baseArchive.SetRealDates(date);
 
diff --git a/SabreTools.FileTypes/BaseArchive.cs b/SabreTools.FileTypes/BaseArchive.cs
index b9460731..9203b3f1 100644
--- a/SabreTools.FileTypes/BaseArchive.cs
+++ b/SabreTools.FileTypes/BaseArchive.cs
@@ -1,12 +1,24 @@
 using System.Collections.Generic;
 using System.IO;
+using SabreTools.Hashing;
+using SabreTools.IO.Logging;
 
 namespace SabreTools.FileTypes
 {
-    public abstract class BaseArchive : Folder
+    public abstract class BaseArchive : BaseFile, IFolder
     {
         #region Protected instance variables
 
+        /// <summary>
+        /// Hashes that are available for children
+        /// </summary>
+        protected HashType[] _hashTypes = [HashType.CRC32, HashType.MD5, HashType.SHA1];
+
+        /// <summary>
+        /// Set of children file objects
+        /// </summary>
+        protected List<BaseFile>? _children;
+
         /// <summary>
         /// Determines if real dates are written
         /// </summary>
@@ -17,6 +29,11 @@ namespace SabreTools.FileTypes
         /// </summary>
         protected const int _bufferSize = 4096 * 128;
 
+        /// <summary>
+        /// Logging object
+        /// </summary>
+        protected Logger _logger;
+
         #endregion
 
         #region Construtors
@@ -24,36 +41,54 @@ namespace SabreTools.FileTypes
         /// <summary>
         /// Create a new Archive with no base file
         /// </summary>
-        public BaseArchive() : base(writeToParent: false) { }
+        public BaseArchive()
+        {
+            _logger = new Logger(this);
+        }
 
         /// <summary>
         /// Create a new BaseArchive from the given file
         /// </summary>
         /// <param name="filename">Name of the file to use</param>
-        public BaseArchive(string filename) : base(filename, writeToParent: false) { }
+        public BaseArchive(string filename) : base(filename)
+        {
+            _logger = new Logger(this);
+        }
 
         #endregion
 
         #region Extraction
 
         /// <inheritdoc/>
-        public override abstract bool CopyAll(string outDir);
+        public abstract bool CopyAll(string outDir);
 
         /// <inheritdoc/>
-        public override abstract string? CopyToFile(string entryName, string outDir);
+        public abstract string? CopyToFile(string entryName, string outDir);
 
         /// <inheritdoc/>
-        public override abstract (Stream?, string?) GetEntryStream(string entryName);
+        public abstract (Stream?, string?) GetEntryStream(string entryName);
 
         #endregion
 
         #region Information
 
-        /// <inheritdoc/>
-        public override abstract List<BaseFile>? GetChildren();
+        /// <summary>
+        /// Set the hash type that can be included in children
+        /// </summary>
+        public void SetHashType(HashType hashType)
+            => SetHashTypes([hashType]);
+
+        /// <summary>
+        /// Set the hash types that can be included in children
+        /// </summary>
+        public void SetHashTypes(HashType[] hashTypes)
+            => _hashTypes = hashTypes;
 
         /// <inheritdoc/>
-        public override abstract List<string> GetEmptyFolders();
+        public abstract List<BaseFile>? GetChildren();
+
+        /// <inheritdoc/>
+        public abstract List<string> GetEmptyFolders();
 
         /// <summary>
         /// Check whether the input file is a standardized format
@@ -73,13 +108,13 @@ namespace SabreTools.FileTypes
         }
 
         /// <inheritdoc/>
-        public override abstract bool Write(string inputFile, string outDir, BaseFile? baseFile);
+        public abstract bool Write(string inputFile, string outDir, BaseFile? baseFile);
 
         /// <inheritdoc/>
-        public override abstract bool Write(Stream? inputStream, string outDir, BaseFile? baseFile);
+        public abstract bool Write(Stream? inputStream, string outDir, BaseFile? baseFile);
 
         /// <inheritdoc/>
-        public override abstract bool Write(List<string> inputFiles, string outDir, List<BaseFile>? baseFiles);
+        public abstract bool Write(List<string> inputFiles, string outDir, List<BaseFile>? baseFiles);
 
         #endregion
     }
diff --git a/SabreTools.FileTypes/FileTypeTool.cs b/SabreTools.FileTypes/FileTypeTool.cs
index d85b7bd4..fc2ce707 100644
--- a/SabreTools.FileTypes/FileTypeTool.cs
+++ b/SabreTools.FileTypes/FileTypeTool.cs
@@ -173,11 +173,11 @@ namespace SabreTools.FileTypes
         }
 
         /// <summary>
-        /// Create an Folder object of the specified type, if possible
+        /// Create an IFolder object of the specified type, if possible
         /// </summary>
         /// <param name="outputFormat">OutputFormat representing the archive to create</param>
-        /// <returns>Archive object representing the inputs</returns>
-        public static Folder? CreateFolderType(OutputFormat outputFormat)
+        /// <returns>IFolder object representing the inputs</returns>
+        public static IFolder? CreateFolderType(OutputFormat outputFormat)
         {
             return outputFormat switch
             {
diff --git a/SabreTools.FileTypes/Folder.cs b/SabreTools.FileTypes/Folder.cs
index 85090fb2..24a60fdf 100644
--- a/SabreTools.FileTypes/Folder.cs
+++ b/SabreTools.FileTypes/Folder.cs
@@ -12,7 +12,7 @@ namespace SabreTools.FileTypes
     /// <summary>
     /// Represents a folder for reading and writing
     /// </summary>
-    public class Folder : BaseFile
+    public class Folder : BaseFile, IFolder
     {
         #region Protected instance variables
 
@@ -31,11 +31,6 @@ namespace SabreTools.FileTypes
         /// </summary>
         protected Logger _logger;
 
-        /// <summary>
-        /// Static logger for static methods
-        /// </summary>
-        protected static Logger _staticLogger = new();
-
         /// <summary>
         /// Flag specific to Folder to omit Machine name from output path
         /// </summary>
@@ -70,12 +65,8 @@ namespace SabreTools.FileTypes
 
         #region Extraction
 
-        /// <summary>
-        /// Attempt to extract a file as an archive
-        /// </summary>
-        /// <param name="outDir">Output directory for archive extraction</param>
-        /// <returns>True if the extraction was a success, false otherwise</returns>
-        public virtual bool CopyAll(string outDir)
+        /// <inheritdoc/>
+        public bool CopyAll(string outDir)
         {
             // If we have an invalid filename
             if (Filename == null)
@@ -138,13 +129,8 @@ namespace SabreTools.FileTypes
             }
         }
 
-        /// <summary>
-        /// Attempt to extract a file from an archive
-        /// </summary>
-        /// <param name="entryName">Name of the entry to be extracted</param>
-        /// <param name="outDir">Output directory for archive extraction</param>
-        /// <returns>Name of the extracted file, null on error</returns>
-        public virtual string? CopyToFile(string entryName, string outDir)
+        /// <inheritdoc/>
+        public string? CopyToFile(string entryName, string outDir)
         {
             string? realentry = null;
 
@@ -181,12 +167,8 @@ namespace SabreTools.FileTypes
             return realentry;
         }
 
-        /// <summary>
-        /// Attempt to extract a stream from an archive
-        /// </summary>
-        /// <param name="entryName">Name of the entry to be extracted</param>
-        /// <returns>Stream representing the entry, null on error</returns>
-        public virtual (Stream?, string?) GetEntryStream(string entryName)
+        /// <inheritdoc/>
+        public (Stream?, string?) GetEntryStream(string entryName)
         {
             // If we have an invalid filename
             if (Filename == null)
@@ -236,11 +218,8 @@ namespace SabreTools.FileTypes
         public void SetHashTypes(HashType[] hashTypes)
             => _hashTypes = hashTypes;
 
-        /// <summary>
-        /// Generate a list of immediate children from the current folder
-        /// </summary>
-        /// <returns>List of BaseFile objects representing the found data</returns>
-        public virtual List<BaseFile>? GetChildren()
+        /// <inheritdoc/>
+        public List<BaseFile>? GetChildren()
         {
             // If we have an invalid filename
             if (Filename == null)
@@ -274,12 +253,8 @@ namespace SabreTools.FileTypes
             return _children;
         }
 
-        /// <summary>
-        /// Generate a list of empty folders in an archive
-        /// </summary>
-        /// <param name="input">Input file to get data from</param>
-        /// <returns>List of empty folders in the folder</returns>
-        public virtual List<string>? GetEmptyFolders()
+        /// <inheritdoc/>
+        public List<string>? GetEmptyFolders()
         {
             return Filename.ListEmpty();
         }
@@ -288,29 +263,15 @@ namespace SabreTools.FileTypes
 
         #region Writing
 
-        /// <summary>
-        /// Write an input file to an output folder
-        /// </summary>
-        /// <param name="inputFile">Input filename to be moved</param>
-        /// <param name="outDir">Output directory to build to</param>
-        /// <param name="baseFile">BaseFile representing the new information</param>
-        /// <returns>True if the write was a success, false otherwise</returns>
-        /// <remarks>This works for now, but it can be sped up by using Ionic.Zip or another zlib wrapper that allows for header values built-in. See edc's code.</remarks>
-        public virtual bool Write(string inputFile, string outDir, BaseFile? baseFile)
+        /// <inheritdoc/>
+        public bool Write(string inputFile, string outDir, BaseFile? baseFile)
         {
             FileStream fs = File.OpenRead(inputFile);
             return Write(fs, outDir, baseFile);
         }
 
-        /// <summary>
-        /// Write an input stream to an output folder
-        /// </summary>
-        /// <param name="inputStream">Input stream to be moved</param>
-        /// <param name="outDir">Output directory to build to</param>
-        /// <param name="baseFile">BaseFile representing the new information</param>
-        /// <returns>True if the write was a success, false otherwise</returns>
-        /// <remarks>This works for now, but it can be sped up by using Ionic.Zip or another zlib wrapper that allows for header values built-in. See edc's code.</remarks>
-        public virtual bool Write(Stream? inputStream, string outDir, BaseFile? baseFile)
+        /// <inheritdoc/>
+        public bool Write(Stream? inputStream, string outDir, BaseFile? baseFile)
         {
             // If either input is null or empty, return
             if (inputStream == null || baseFile == null || baseFile.Filename == null)
@@ -388,14 +349,8 @@ namespace SabreTools.FileTypes
             }
         }
 
-        /// <summary>
-        /// Write a set of input files to an output folder (assuming the same output archive name)
-        /// </summary>
-        /// <param name="inputFiles">Input files to be moved</param>
-        /// <param name="outDir">Output directory to build to</param>
-        /// <param name="baseFiles">BaseFiles representing the new information</param>
-        /// <returns>True if the inputs were written properly, false otherwise</returns>
-        public virtual bool Write(List<string> inputFiles, string outDir, List<BaseFile>? baseFiles)
+        /// <inheritdoc/>
+        public bool Write(List<string> inputFiles, string outDir, List<BaseFile>? baseFiles)
         {
             throw new NotImplementedException();
         }
diff --git a/SabreTools.FileTypes/IFolder.cs b/SabreTools.FileTypes/IFolder.cs
new file mode 100644
index 00000000..b3348bc7
--- /dev/null
+++ b/SabreTools.FileTypes/IFolder.cs
@@ -0,0 +1,85 @@
+using System.Collections.Generic;
+using System.IO;
+
+namespace SabreTools.FileTypes
+{
+    /// <summary>
+    /// Represents an item that can contain children
+    /// </summary>
+    public interface IFolder
+    {
+        #region Extraction
+
+        /// <summary>
+        /// Attempt to extract a file as an archive
+        /// </summary>
+        /// <param name="outDir">Output directory for archive extraction</param>
+        /// <returns>True if the extraction was a success, false otherwise</returns>
+        bool CopyAll(string outDir);
+
+        /// <summary>
+        /// Attempt to extract a file from an archive
+        /// </summary>
+        /// <param name="entryName">Name of the entry to be extracted</param>
+        /// <param name="outDir">Output directory for archive extraction</param>
+        /// <returns>Name of the extracted file, null on error</returns>
+        string? CopyToFile(string entryName, string outDir);
+
+        /// <summary>
+        /// Attempt to extract a stream from an archive
+        /// </summary>
+        /// <param name="entryName">Name of the entry to be extracted</param>
+        /// <returns>Stream representing the entry, null on error</returns>
+        (Stream?, string?) GetEntryStream(string entryName);
+
+        #endregion
+
+        #region Information
+
+        /// <summary>
+        /// Generate a list of immediate children from the current folder
+        /// </summary>
+        /// <returns>List of BaseFile objects representing the found data</returns>
+        List<BaseFile>? GetChildren();
+
+        /// <summary>
+        /// Generate a list of empty folders in an archive
+        /// </summary>
+        /// <param name="input">Input file to get data from</param>
+        /// <returns>List of empty folders in the folder</returns>
+        List<string>? GetEmptyFolders();
+
+        #endregion
+
+        #region Writing
+
+        /// <summary>
+        /// Write an input file to an output folder
+        /// </summary>
+        /// <param name="inputFile">Input filename to be moved</param>
+        /// <param name="outDir">Output directory to build to</param>
+        /// <param name="baseFile">BaseFile representing the new information</param>
+        /// <returns>True if the write was a success, false otherwise</returns>
+        bool Write(string inputFile, string outDir, BaseFile? baseFile);
+
+        /// <summary>
+        /// Write an input stream to an output folder
+        /// </summary>
+        /// <param name="inputStream">Input stream to be moved</param>
+        /// <param name="outDir">Output directory to build to</param>
+        /// <param name="baseFile">BaseFile representing the new information</param>
+        /// <returns>True if the write was a success, false otherwise</returns>
+        bool Write(Stream? inputStream, string outDir, BaseFile? baseFile);
+
+        /// <summary>
+        /// Write a set of input files to an output folder (assuming the same output archive name)
+        /// </summary>
+        /// <param name="inputFiles">Input files to be moved</param>
+        /// <param name="outDir">Output directory to build to</param>
+        /// <param name="baseFiles">BaseFiles representing the new information</param>
+        /// <returns>True if the inputs were written properly, false otherwise</returns>
+        bool Write(List<string> inputFiles, string outDir, List<BaseFile>? baseFiles);
+
+        #endregion
+    }
+}
\ No newline at end of file