diff --git a/EnvelopeGenerator.Web/Models/Annotation.cs b/EnvelopeGenerator.Web/Models/Annotation.cs
index c730939f..58262e7b 100644
--- a/EnvelopeGenerator.Web/Models/Annotation.cs
+++ b/EnvelopeGenerator.Web/Models/Annotation.cs
@@ -1,6 +1,6 @@
 namespace EnvelopeGenerator.Web.Models;
 
-public record Annotation(string? HorBoundAnnotId = null, string? VerBoundAnnotId = null)
+public record Annotation(string? HorBoundAnnotName = null, string? VerBoundAnnotName = null)
 {
     #region Layout
     internal double _marginX = default;
diff --git a/EnvelopeGenerator.Web/Models/AnnotationParams.cs b/EnvelopeGenerator.Web/Models/AnnotationParams.cs
index 864cef88..9df111f3 100644
--- a/EnvelopeGenerator.Web/Models/AnnotationParams.cs
+++ b/EnvelopeGenerator.Web/Models/AnnotationParams.cs
@@ -2,5 +2,30 @@
 
 public class AnnotationParams
 {
-    public required Dictionary<string, Annotation> Annotations { get; init; }
+    private readonly Dictionary<string, Annotation> _annots = new();
+
+    public required Dictionary<string, Annotation> Annots
+    {
+        get => _annots;
+        init
+        {
+            // set bound annotations
+            foreach (var name in _annots.Keys)
+            {
+                // horizontal
+                if (_annots[name].HorBoundAnnotName is string horBoundAnnotName)
+                    if (_annots.TryGetValue(horBoundAnnotName, out var horBoundAnnot))
+                        _annots[name].HorBoundAnnot = horBoundAnnot;
+                else
+                    throw new InvalidOperationException($"{horBoundAnnotName} added as bound anotation. However, it is not defined.");
+
+                // vertical
+                if (_annots[name].VerBoundAnnotName is string verBoundAnnotName)
+                    if (_annots.TryGetValue(verBoundAnnotName, out var verBoundAnnot))
+                        _annots[name].VerBoundAnnot = verBoundAnnot;
+                    else
+                        throw new InvalidOperationException($"{verBoundAnnotName} added as bound anotation. However, it is not defined.");
+            }
+        }
+    }
 }