diff --git a/crates/ui-egui/src/print_view.rs b/crates/ui-egui/src/print_view.rs
index 7c1ab85fb1..245c126ae9 100644
--- a/crates/ui-egui/src/print_view.rs
+++ b/crates/ui-egui/src/print_view.rs
@@ -729,8 +729,13 @@ fn paint_cell(
     }
     let clip = painter.with_clip_rect(avail.intersect(painter.clip_rect()));
     let tex = photo.and_then(|id| {
-        let px = (shown.width().max(shown.height()) * 2.0).clamp(64.0, 1024.0) as usize;
-        crate::panels::grid::request_thumb(app, id, px, 10);
+        // Use the library's thumbnail when there is one. A thumbnail is kept at one size, so asking
+        // for another size here every frame made the preview and the grid behind the dialog
+        // re-render each other's thumbnail for as long as the dialog stayed open.
+        if app.renderer.thumb(id).is_none() {
+            let px = (shown.width().max(shown.height()) * 2.0).clamp(64.0, 1024.0) as usize;
+            crate::panels::grid::request_thumb(app, id, px, 10);
+        }
         app.renderer.thumb(id).map(|tex| tex.tex.id())
     });
     match tex {
diff --git a/crates/ui-egui/src/tests_print.rs b/crates/ui-egui/src/tests_print.rs
index 6dbea7a40e..a75191d038 100644
--- a/crates/ui-egui/src/tests_print.rs
+++ b/crates/ui-egui/src/tests_print.rs
@@ -298,3 +298,26 @@ fn the_print_dialog_fits_the_window_with_its_buttons_on_screen() {
         }
     }
 }
+
+#[test]
+fn the_print_preview_does_not_rebuild_thumbnails_every_frame() {
+    let mut h = demo(Services { png: None, ..Default::default() });
+    let before = h.app.renderer.thumb_jobs_built;
+    cmd(&mut h, "dialog.print", json!({}));
+    for style in ["contactSheet", "picturePackage", "singleImage"] {
+        cmd(&mut h, "print.set", json!({"layout": {"style": style}}));
+        if style == "picturePackage" {
+            // the same photo in cells of different sizes
+            cmd(&mut h, "print.cell.add", json!({"width": 2.0, "height": 2.5}));
+            cmd(&mut h, "print.cell.add", json!({"width": 5.0, "height": 7.0}));
+        }
+        assert!(h.settle(Duration::from_secs(5)), "{style}: the dialog settles");
+        let built = h.app.renderer.thumb_jobs_built;
+        for _ in 0..60 {
+            h.step();
+        }
+        assert_eq!(h.app.renderer.thumb_jobs_built, built, "{style}: no thumbnail is rebuilt while nothing changes");
+        assert_eq!(h.app.renderer.in_flight(), 0, "{style}");
+    }
+    assert!(h.app.renderer.thumb_jobs_built - before < 50, "{} jobs", h.app.renderer.thumb_jobs_built - before);
+}