diff --git a/.issueflows/03-solved-issues/issue801_original.md b/.issueflows/03-solved-issues/issue801_original.md
new file mode 100644
index 00000000..0684a737
--- /dev/null
+++ b/.issueflows/03-solved-issues/issue801_original.md
@@ -0,0 +1,9 @@
+# Issue #801: App-friendly collected figures: theme / label / height hook (or pass a FigureSpec)
+
+Source: https://github.com/jepegit/cellpy/issues/801
+
+## Original issue text
+
+Split from #791 (item c). `collected_plot` returns faceted figures with default plotly styling (mirror axis boxes, right-side facet titles spelled `variable=charge_capacity_gravimetric`, auto height growing with facet count). A **theme / label / height hook** (or a `FigureSpec` the caller can pass) would let apps drop the figure in without re-styling every one.
+
+Relates to the plotting `FigureSpec` pipeline and SPEED-30 label work.
diff --git a/.issueflows/03-solved-issues/issue801_plan.md b/.issueflows/03-solved-issues/issue801_plan.md
new file mode 100644
index 00000000..01f42f35
--- /dev/null
+++ b/.issueflows/03-solved-issues/issue801_plan.md
@@ -0,0 +1,98 @@
+# Issue #801 — Plan: App-friendly collected figures (theme / label / height)
+
+Status: **confirmed** (2026-07-31) — open questions resolved as recommended:
+pretty labels default; no `spec=` this PR; include `layout_updates`.
+
+## Goal
+
+Give apps first-class, documented knobs on `collected_plot` / `Collection.plot` so faceted Plotly figures can be dropped into an app shell without a private restyle pass — covering **template/theme**, **facet labels**, and **height**.
+
+## Constraints
+
+- Patch release (`v.2.1.2`); stay on the **collected** Plotly path (`Collection.plot` → `collected_plot` → `summary_plotter` / `_cycles_plotter`). Do not rework single-cell prepare→render.
+- Collected path still builds a thin `FigureSpec` (extras only; panels unused) — same as #804. Do **not** force a full PanelSpec migration.
+- Prefer additive kwargs + clearer defaults over a new theming framework.
+- Companion context: [cellpy/cellpy-simple-gui](https://github.com/cellpy/cellpy-simple-gui) pain-point §11 (restyles every figure today); #804 already landed `share_y` / `y_ranges`.
+- Design docs: [plotting-collected.md](../04-designs-and-guides/plotting-collected.md), [plotting-backends.md](../04-designs-and-guides/plotting-backends.md).
+
+### Prior art
+
+| Hit | Where | Relation |
+| --- | --- | --- |
+| Hardcoded `template = f"{PLOTLY_BASE_TEMPLATE}+{method}"` | [`collected.py`](../../cellpy/plotting/collected.py) `_cycles_plotter` | Theme seam — no public override today |
+| `make_collector_templates` / `make_plotly_template` | [`theme.py`](../../cellpy/plotting/theme.py) | Axis chrome only; apps still restyle paper/legend/facet strip |
+| `y_label_mapper` + `_plotly_y_label_cleaner` | `sequence_plotter` / `summary_plotter` | Label seam exists; only populated when `units=` is passed (Batch path). Plain `Collection.plot` keeps `variable=…` facet titles |
+| `height` / `sub_fig_min_height` / `figure_border_height` | `_cycles_plotter` | Height seam exists but names are obscure; summary forces `sub_fig_min_height=300` |
+| `plotly_template` on single-cell prepare configs | `prepare/{summary,curves,ica}.py` | Naming to mirror for collected override |
+| Thin `FigureSpec(extras=…)` in `collected_plot` | [`collected.py`](../../cellpy/plotting/collected.py) | Escape hatch possible via merging `render_opts`; panels still ignored |
+| Toolbox / graphify | `.issueflows/00-tools/`, `graphify-out/` | No plotting-theme helper |
+
+## Approach
+
+Ship **three public knobs** (kwargs through `Collection.plot` / `collected_plot` → `render_opts`), document them, and improve the default label path so apps are not forced to pass `units=` just to drop `variable=`.
+
+### 1. Theme / template
+
+- Accept `plotly_template=` (string; Plotly template name or `"+"`-combined). When set, use it in `_cycles_plotter`'s `fig.update_layout(template=…)` instead of hardcoding `simple_white+{method}`.
+- Accept optional `layout_updates: Mapping[str, Any]` applied after the collector layout (paper/plot bgcolor, margin, legend dict patches). Keep this a shallow `update_layout(**layout_updates)` — not a second theme system.
+- Out of scope: new light/dark token packs, discrete colorway registry (existing `palette=` / `palette_*` stay as-is).
+
+### 2. Labels (facet strip / y titles)
+
+- When `y_label_mapper` is omitted, build a **default pretty mapper** from the frame's `variable` values (title-case / split `_`, optional unit suffix only if `units=` present — reuse the existing units branch). Always strip Plotly's `variable=` annotation text (move facet label onto the y-axis title and clear the side strip), matching today's `y_label_mapper` behaviour.
+- Keep explicit `y_label_mapper=` as override (wins over the default).
+- Gate the new default behind `pretty_labels=True` **if** Open question 1 chooses opt-in; otherwise make it the summary default (recommended).
+
+### 3. Height
+
+- Document and prefer public names:
+  - `height=` — absolute figure height (already works).
+  - `height_per_panel=` — alias of `sub_fig_min_height` (clearer for apps).
+  - keep `figure_border_height=` / `sub_fig_min_height=` as synonyms.
+- Ensure summary's internal default (`300` per panel) still applies when neither absolute `height` nor `height_per_panel` is given.
+- No change to the experimental `height_fractions` path.
+
+### 4. Optional `spec=` (thin)
+
+- Allow `collected_plot(..., spec=FigureSpec)` / `spec=` on `Collection.plot`: merge `spec.extras["render_opts"]` into opts, honour `spec.title`, and if `spec.extras` carries `plotly_template` / `layout_updates`, treat them like the kwargs above. Still ignore `panels` (same as #804).
+- If Open question 2 says kwargs-only, skip this bullet.
+
+### 5. Docs
+
+- Update `plotting-collected.md` with the three knobs + a short app example.
+- Docstrings on `collected_plot` / `Collection.plot` / `summary_plotter`.
+- Tiny example in existing plotting/collect docs if a natural home exists (no new guide).
+
+## Files to touch
+
+| Path | Change |
+| --- | --- |
+| [`cellpy/plotting/collected.py`](../../cellpy/plotting/collected.py) | `plotly_template`, `layout_updates`, default/`pretty_labels` mapper, `height_per_panel` alias; optional `spec=` merge; docstrings |
+| [`cellpy/collect/collection.py`](../../cellpy/collect/collection.py) | Docstring mention of the new knobs |
+| [`.issueflows/04-designs-and-guides/plotting-collected.md`](../04-designs-and-guides/plotting-collected.md) | Decision bullets + example |
+| `tests/test_collected_summary_axes.py` or new `tests/test_collected_app_hooks.py` | Assert template override, pretty labels (no `variable=`), height math |
+
+## Test strategy
+
+```bash
+uv run pytest tests/test_collected_summary_axes.py tests/test_collected_app_hooks.py -q
+MPLBACKEND=Agg uv run pytest -m essential
+```
+
+- Synthetic long summary frame (reuse #804 helper pattern).
+- Assert: with `plotly_template="plotly_white"`, layout template reflects it; with default/pretty labels, annotations empty or lack `variable=`; with `height_per_panel=180` and 2 variables, `layout.height == figure_border_height + 2*180` (or documented formula).
+- Mark essential only if cheap (same bar as #804).
+
+## Open questions
+
+1. **Pretty labels default?**  
+   - **Recommended: yes** — summary collected path always builds a pretty mapper when `y_label_mapper` is omitted (visual change: side `variable=…` strip goes away; y-axis titles become humanized).  
+   - Alternative: opt-in `pretty_labels=True`.
+
+2. **`spec=` escape hatch this PR?**  
+   - **Recommended: no** — kwargs cover the issue text; thin `FigureSpec` merge can wait.  
+   - Alternative: accept `spec=` merge as above.
+
+3. **`layout_updates=` this PR?**  
+   - **Recommended: yes** (small; unblocks paper/plot colors without a template factory).  
+   - Alternative: template string only.
diff --git a/.issueflows/03-solved-issues/issue801_status.md b/.issueflows/03-solved-issues/issue801_status.md
new file mode 100644
index 00000000..e772340a
--- /dev/null
+++ b/.issueflows/03-solved-issues/issue801_status.md
@@ -0,0 +1,21 @@
+# Issue #801 — Status
+
+- [x] Done
+
+## What's done
+
+- Plan accepted (pretty labels default; no `spec=`; include `layout_updates`).
+- Implemented on collected Plotly path:
+  - `plotly_template=` override
+  - `layout_updates=` after collector layout
+  - default pretty `y_label_mapper` (clears `variable=…` facet strip)
+  - `height_per_panel=` alias of `sub_fig_min_height`
+  - `y_ranges` applied before label cleanup (keeps #804 working with pretty labels)
+- Docs: `plotting-collected.md`, docstrings on `collected_plot` / `Collection.plot` / `summary_plotter`.
+- Tests: `tests/test_collected_app_hooks.py` + updated `tests/test_collected_summary_axes.py`.
+- `HISTORY.md` Unreleased bullet added.
+- Essential suite green (`635 passed`); PR https://github.com/jepegit/cellpy/pull/808
+
+## Remaining work
+
+- None — ready for merge / `/iflow-cleanup` after merge.
diff --git a/.issueflows/04-designs-and-guides/plotting-collected.md b/.issueflows/04-designs-and-guides/plotting-collected.md
index 2f7f2a69..d686284d 100644
--- a/.issueflows/04-designs-and-guides/plotting-collected.md
+++ b/.issueflows/04-designs-and-guides/plotting-collected.md
@@ -34,6 +34,13 @@ Epic #567 Stage 3 / issue #657 re-bases collectors' drawing half onto
   `y_ranges={"coulombic_efficiency": [0, 110], ...}` (variable → `[lo, hi]`).
   Non-empty `y_ranges` forces independent axes. Plotly is the supported
   backend for `y_ranges`; seaborn/matplotlib are best-effort and ignore it.
+- **App chrome (#801):** `plotly_template=` overrides the default
+  `plotly+{method}` combo; `layout_updates=` is a shallow
+  `fig.update_layout(**…)` after collector styling. Summary facet strips no
+  longer keep raw `variable=…` text by default — pretty y-axis titles are
+  built automatically (`y_label_mapper=` overrides). Height:
+  `height=` (absolute) or `height_per_panel=` (alias of `sub_fig_min_height`;
+  summary default 300 px/panel) plus optional `figure_border_height=`.
 
 ### Example — Capacity + CE without crushing panels
 
@@ -45,9 +52,22 @@ collection.plot(
 )
 ```
 
+### Example — drop into an app shell
+
+```python
+collection.plot(
+    family_kind="summary",
+    plotly_template="plotly_white",
+    layout_updates={"paper_bgcolor": "#f7f7f7", "margin": dict(l=60, r=20, t=40, b=40)},
+    height_per_panel=220,
+    y_ranges={"coulombic_efficiency": [0, 110]},
+)
+```
+
 ## Links
 
 - Issue #657; epic #567; plan
   `architecture-plan/cellpy2-plotting-redesign-plan.md` §3.3 / Phase 4
 - Related: `plotting-prepare.md`, `plotting-backends.md`
 - Issue #804 (per-panel y-limits / `share_y`)
+- Issue #801 (theme / label / height hooks)
diff --git a/HISTORY.md b/HISTORY.md
index 9e696144..ed7a912b 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -2,6 +2,9 @@
 
 ## [Unreleased]
 
+* App-friendly collected figures: theme / label / height hook (or pass a
+  FigureSpec). (#801)
+
 ## [2.1.1.post3] - 2026-07-30
 
 Post-release of 2.1.1 — silence loader-discovery WARNING spam for apps.
diff --git a/cellpy/collect/collection.py b/cellpy/collect/collection.py
index f7289fcd..6cfb7117 100644
--- a/cellpy/collect/collection.py
+++ b/cellpy/collect/collection.py
@@ -83,7 +83,9 @@ def plot(self, *, family_kind: str | None = None, **kwargs):
 
         For summary collections (Plotly), pass ``share_y`` / ``match_axes`` and
         optional ``y_ranges={variable: [lo, hi], ...}`` for per-facet y-limits
-        (see :func:`cellpy.plotting.collected.summary_plotter`).
+        (see :func:`cellpy.plotting.collected.summary_plotter`). App chrome:
+        ``plotly_template``, ``layout_updates``, ``y_label_mapper``,
+        ``height`` / ``height_per_panel``.
         """
         from cellpy.plotting import collected_plot
 
diff --git a/cellpy/plotting/collected.py b/cellpy/plotting/collected.py
index 21b6e956..109eebdc 100644
--- a/cellpy/plotting/collected.py
+++ b/cellpy/plotting/collected.py
@@ -540,6 +540,9 @@ def sequence_plotter(
         elif method == "summary":
             logging.info("sequence-plotter - summary plotly")
 
+        # Must not reach px.line / spread_plot (unknown kwarg).
+        y_ranges = kwargs.pop("y_ranges", None) or {}
+
         abs_facet_row_spacing = kwargs.pop("abs_facet_row_spacing", 20)
         abs_facet_col_spacing = kwargs.pop("abs_facet_col_spacing", 20)
         facet_row_spacing = kwargs.pop(
@@ -630,6 +633,11 @@ def sequence_plotter(
                 except Exception as e:
                     print(f"sequence_plotter - summary - failed {e} [{group}]")
 
+            # Apply per-panel y-limits while facet annotations still spell
+            # ``variable=…`` (#804 / #801). Pretty-label cleanup clears them.
+            if y_ranges and not spread:
+                _apply_summary_y_ranges(fig, y_ranges, facet=g)
+
             if y_label_mapper and not spread:
                 y_label_mapper = _plotly_y_label_cleaner(y_label_mapper)
                 annotations = fig.layout.annotations
@@ -867,6 +875,61 @@ def _resolve_share_y(
     return bool(default)
 
 
+def _pretty_variable_label(variable: str, units: Any = None) -> str:
+    """Humanize a summary ``variable`` column name for facet / y-axis titles.
+
+    Strips specific-mode suffixes (``_gravimetric`` / ``_areal`` / …). When
+    ``units`` is the Batch-style dict used by :func:`summary_plotter`, appends
+    a parenthetical unit; otherwise returns the title-cased name alone.
+    """
+    v = str(variable)
+    u_sub = None
+    if units:
+        cellpy_units = units["cellpy_units"]
+        if v.endswith("_areal") or v.endswith("_areal_cv"):
+            u_sub = cellpy_units.specific_areal
+        elif v.endswith("_gravimetric") or v.endswith("_gravimetric_cv"):
+            u_sub = cellpy_units.specific_gravimetric
+        elif v.endswith("_volumetric") or v.endswith("_volumetric_cv"):
+            u_sub = cellpy_units.specific_volumetric
+
+    u_top = None
+    if units:
+        cellpy_units = units["cellpy_units"]
+        if "_capacity" in v:
+            u_top = cellpy_units.charge
+        if "_norm" in v:
+            u_top = "normalized"
+        if v == "coulombic_efficiency":
+            u_top = "%"
+
+    parts = v.split("_")
+    mode_suffixes = {"gravimetric", "areal", "volumetric"}
+    if parts and parts[-1] == "cv" and len(parts) >= 2 and parts[-2] in mode_suffixes:
+        parts = parts[:-2] + ["cv"]
+    elif parts and parts[-1] in mode_suffixes:
+        parts = parts[:-1]
+    label = " ".join(parts).title()
+    if label.endswith("Cv"):
+        label = label.replace("Cv", "CV")
+
+    if not units:
+        return label
+
+    u = u_top or "Value"
+    if u_sub:
+        u_sub = str(u_sub).replace("**", "")
+        u = f"{u}/{u_sub}"
+    return f"{label} ({u})"
+
+
+def _default_summary_y_label_mapper(
+    variables: list[str], units: Any = None
+) -> dict[str, str]:
+    """Build ``variable → pretty label`` for collected summary facets (#801)."""
+    return {v: _pretty_variable_label(v, units=units) for v in variables}
+
+
 def _yaxis_key_for_facet_label(fig: Any, label: str) -> Optional[str]:
     """Map a Plotly facet annotation text to its ``yaxis`` / ``yaxisN`` key."""
     annotations = getattr(fig.layout, "annotations", None) or ()
@@ -897,6 +960,32 @@ def _yaxis_key_for_facet_label(fig: Any, label: str) -> Optional[str]:
     return best_key
 
 
+def _yaxis_key_for_variable(
+    fig: Any, variable: str, *, facet: str = "variable"
+) -> Optional[str]:
+    """Resolve a summary facet row's y-axis key by annotation or axis title.
+
+    Prefer the Plotly ``variable=…`` facet strip (present before pretty-label
+    cleanup). After labels move onto y-axis titles, match the pretty title.
+    """
+    key = _yaxis_key_for_facet_label(fig, f"{facet}={variable}")
+    if key is not None:
+        return key
+    pretty = _pretty_variable_label(variable)
+    for layout_key in fig.layout:
+        key_s = str(layout_key)
+        if not key_s.startswith("yaxis"):
+            continue
+        title = getattr(fig.layout[layout_key].title, "text", None)
+        if not title:
+            continue
+        if title == pretty or title.startswith(f"{pretty} ") or title.startswith(
+            f"{pretty} ("
+        ):
+            return key_s
+    return None
+
+
 _warned_unknown_y_range_keys: set[str] = set()
 
 
@@ -926,7 +1015,7 @@ def _apply_summary_y_ranges(
                 stacklevel=3,
             )
             continue
-        axis_key = _yaxis_key_for_facet_label(fig, f"{facet}={variable}")
+        axis_key = _yaxis_key_for_variable(fig, variable, facet=facet)
         if axis_key is None:
             if variable not in _warned_unknown_y_range_keys:
                 _warned_unknown_y_range_keys.add(variable)
@@ -982,8 +1071,16 @@ def _cycles_plotter(
     legend_title = kwargs.pop("legend_title", None)
     show_legend = kwargs.pop("show_legend", None)
     cols = kwargs.pop("cols", 3)
+    height_per_panel = kwargs.pop("height_per_panel", None)
+    sub_fig_min_height_explicit = "sub_fig_min_height" in kwargs
     sub_fig_min_height = kwargs.pop("sub_fig_min_height", 200)
+    if height_per_panel is not None:
+        sub_fig_min_height = height_per_panel
     figure_border_height = kwargs.pop("figure_border_height", 100)
+    plotly_template = kwargs.pop("plotly_template", None)
+    layout_updates = kwargs.pop("layout_updates", None) or {}
+    if layout_updates and not isinstance(layout_updates, dict):
+        raise TypeError("layout_updates must be a dict of Plotly layout kwargs")
     # kwargs from default `BatchCollector.render` method not used by `sequence_plotter`:
     journal = kwargs.pop("journal", None)
     units = kwargs.pop("units", None)
@@ -1012,7 +1109,10 @@ def _cycles_plotter(
             number_of_figs = len(collected_curves[z].unique())
     elif method == "summary":
         number_of_figs = len(collected_curves["variable"].unique())
-        sub_fig_min_height = 300
+        # Default 300 px/panel unless the caller set height_per_panel or
+        # sub_fig_min_height explicitly (#801).
+        if height_per_panel is None and not sub_fig_min_height_explicit:
+            sub_fig_min_height = 300
     else:
         number_of_figs = 1
 
@@ -1042,7 +1142,11 @@ def _cycles_plotter(
 
     # Rendering:
     if backend == "plotly":
-        template = f"{PLOTLY_BASE_TEMPLATE}+{method}"
+        template = (
+            plotly_template
+            if plotly_template is not None
+            else f"{PLOTLY_BASE_TEMPLATE}+{method}"
+        )
 
         legend_orientation = "v"
         if legend_position == "bottom":
@@ -1064,6 +1168,8 @@ def _cycles_plotter(
             height=height,
             width=width,
         )
+        if layout_updates:
+            fig.update_layout(**layout_updates)
         if not match_axes:
             fig.update_yaxes(matches=None)
             fig.update_xaxes(matches=None)
@@ -1086,6 +1192,15 @@ def summary_plotter(collected_curves, cycles_to_plot=None, backend="plotly", **k
     - ``y_ranges``: mapping of ``variable`` name → ``[lo, hi]`` for per-panel
       fixed limits. Omitted variables keep autorange. A non-empty ``y_ranges``
       forces independent axes. Supported for ``backend="plotly"`` only.
+
+    App-facing chrome (Plotly, #801):
+
+    - ``plotly_template``: override the default ``plotly+summary`` template.
+    - ``layout_updates``: dict passed to ``fig.update_layout`` after collector styling.
+    - ``y_label_mapper``: ``variable → label``; when omitted, pretty labels are
+      built automatically (facet ``variable=…`` strip cleared).
+    - ``height`` / ``height_per_panel`` (alias of ``sub_fig_min_height``) /
+      ``figure_border_height``: absolute or per-panel height control.
     """
 
     # start_cell is used to determine the starting cell for the subplots (plotly)
@@ -1177,9 +1292,7 @@ def summary_plotter(collected_curves, cycles_to_plot=None, backend="plotly", **k
         group_cells = kwargs.pop("group_cells", True)
 
     units = kwargs.pop("units", None)
-    label_mapper = {
-        f"{y}": None,
-    }
+    explicit_y_label_mapper = kwargs.pop("y_label_mapper", None)
     # order the variables by a given order:
     order_variables = kwargs.pop("order_variables", None)
     if order_variables:
@@ -1188,45 +1301,12 @@ def summary_plotter(collected_curves, cycles_to_plot=None, backend="plotly", **k
         )
         collected_curves = collected_curves.sort_values(by=[g, z, x])
 
-    if units:
-        label_mapper[y] = {}
-        variables = list(collected_curves[g].unique())
-        for v in variables:
-            # unit label
-            u_sub = None
-            if v.endswith("_areal") or v.endswith("_areal_cv"):
-                u_sub = units["cellpy_units"].specific_areal
-            elif v.endswith("_gravimetric") or v.endswith("_gravimetric_cv"):
-                u_sub = units["cellpy_units"].specific_gravimetric
-            elif v.endswith("_volumetric") or v.endswith("_volumetric_cv"):
-                u_sub = units["cellpy_units"].specific_volumetric
-
-            u_top = None
-            if "_capacity" in v:
-                u_top = units["cellpy_units"].charge
-            if "_norm" in v:
-                u_top = "normalized"
-            if v == "coulombic_efficiency":
-                u_top = "%"
-
-            u = u_top or "Value"
-
-            # variable label
-            v2 = v.split("_")
-            if u_sub:
-                u_sub = u_sub.replace("**", "")
-                u = f"{u}/{u_sub}"
-                if v2[-1] == "cv":
-                    v2 = v2[:-2]
-                    v2.append("cv")
-                else:
-                    v2 = v2[:-1]
-            v2 = " ".join(v2).title()
-
-            if v2.endswith("Cv"):
-                v2 = v2.replace("Cv", "CV")
-
-            label_mapper[y][v] = f"{v2} ({u})"
+    variables = list(collected_curves[g].unique())
+    if explicit_y_label_mapper is not None:
+        y_label_mapper = explicit_y_label_mapper
+    else:
+        # Default pretty labels so apps are not stuck with ``variable=…`` (#801).
+        y_label_mapper = _default_summary_y_label_mapper(variables, units=units)
 
     # TODO: need to refactor and fix how the classes are created so that leftover kwargs are not sent to the backend
     #  (for example if another collector is used and registers a kwarg without popping it)
@@ -1243,7 +1323,7 @@ def summary_plotter(collected_curves, cycles_to_plot=None, backend="plotly", **k
         standard_deviation=standard_deviation,
         x_label=x_label,
         x_unit=x_unit,
-        y_label_mapper=label_mapper[y],
+        y_label_mapper=y_label_mapper,
         group_cells=group_cells,
         default_title="Summary Plot",
         backend=backend,
@@ -1251,6 +1331,7 @@ def summary_plotter(collected_curves, cycles_to_plot=None, backend="plotly", **k
         cycles=cycles_to_plot,
         cols=cols,
         match_axes=share_y_resolved,
+        y_ranges=y_ranges,
         **kwargs,
     )
 
@@ -1565,6 +1646,9 @@ def collected_plot(
             For ``family_kind="summary"`` (Plotly): ``share_y`` / ``match_axes``
             control shared vs independent facet y-scales (default independent);
             ``y_ranges`` maps variable name → ``[lo, hi]`` for per-panel limits.
+            App chrome (#801): ``plotly_template``, ``layout_updates``,
+            ``y_label_mapper`` (pretty labels by default), ``height`` /
+            ``height_per_panel`` / ``figure_border_height``.
 
     Returns:
         Backend-native figure object.
diff --git a/tests/test_collected_app_hooks.py b/tests/test_collected_app_hooks.py
new file mode 100644
index 00000000..88d4c448
--- /dev/null
+++ b/tests/test_collected_app_hooks.py
@@ -0,0 +1,165 @@
+"""Collected summary app chrome: template / labels / height (#801)."""
+
+from __future__ import annotations
+
+import pandas as pd
+import pytest
+
+from cellpy.plotting.collected import (
+    _default_summary_y_label_mapper,
+    _pretty_variable_label,
+)
+
+
+def _summary_frame() -> pd.DataFrame:
+    rows = []
+    for cell in ("a", "b"):
+        for cycle in (1, 2, 3):
+            rows.append(
+                {
+                    "cycle": cycle,
+                    "cell": cell,
+                    "group": 1,
+                    "sub_group": 1,
+                    "variable": "charge_capacity_gravimetric",
+                    "value": 100.0 + cycle,
+                }
+            )
+            rows.append(
+                {
+                    "cycle": cycle,
+                    "cell": cell,
+                    "group": 1,
+                    "sub_group": 1,
+                    "variable": "coulombic_efficiency",
+                    "value": 98.0,
+                }
+            )
+    return pd.DataFrame(rows)
+
+
+@pytest.mark.essential
+def test_pretty_variable_label_strips_mode_suffix():
+    assert _pretty_variable_label("charge_capacity_gravimetric") == "Charge Capacity"
+    assert _pretty_variable_label("coulombic_efficiency") == "Coulombic Efficiency"
+    assert _pretty_variable_label("discharge_capacity_areal_cv") == "Discharge Capacity CV"
+
+
+@pytest.mark.essential
+def test_default_summary_y_label_mapper():
+    mapper = _default_summary_y_label_mapper(
+        ["charge_capacity_gravimetric", "coulombic_efficiency"]
+    )
+    assert mapper["charge_capacity_gravimetric"] == "Charge Capacity"
+    assert mapper["coulombic_efficiency"] == "Coulombic Efficiency"
+
+
+@pytest.mark.essential
+def test_summary_pretty_labels_clear_variable_facet_strip():
+    pytest.importorskip("plotly", reason="plotting extras (batch) not installed")
+    from cellpy.plotting import theme
+    from cellpy.plotting.collected import summary_plotter
+
+    theme.make_collector_templates()
+    fig = summary_plotter(_summary_frame(), backend="plotly", group_cells=False)
+    assert fig is not None
+    texts = [getattr(a, "text", None) or "" for a in (fig.layout.annotations or ())]
+    assert not any(t.startswith("variable=") for t in texts)
+    y_titles = [
+        fig.layout[k].title.text
+        for k in fig.layout
+        if str(k).startswith("yaxis") and fig.layout[k].title.text
+    ]
+    assert "Charge Capacity" in y_titles
+    assert "Coulombic Efficiency" in y_titles
+
+
+@pytest.mark.essential
+def test_summary_explicit_y_label_mapper_wins():
+    pytest.importorskip("plotly", reason="plotting extras (batch) not installed")
+    from cellpy.plotting import theme
+    from cellpy.plotting.collected import summary_plotter
+
+    theme.make_collector_templates()
+    fig = summary_plotter(
+        _summary_frame(),
+        backend="plotly",
+        group_cells=False,
+        y_label_mapper={
+            "charge_capacity_gravimetric": "Cap",
+            "coulombic_efficiency": "CE",
+        },
+    )
+    y_titles = [
+        fig.layout[k].title.text
+        for k in fig.layout
+        if str(k).startswith("yaxis") and fig.layout[k].title.text
+    ]
+    assert "Cap" in y_titles
+    assert "CE" in y_titles
+
+
+@pytest.mark.essential
+def test_summary_plotly_template_and_layout_updates():
+    pytest.importorskip("plotly", reason="plotting extras (batch) not installed")
+    from cellpy.plotting import theme
+    from cellpy.plotting.collected import summary_plotter
+
+    theme.make_collector_templates()
+    fig_default = summary_plotter(
+        _summary_frame(), backend="plotly", group_cells=False
+    )
+    fig = summary_plotter(
+        _summary_frame(),
+        backend="plotly",
+        group_cells=False,
+        plotly_template="plotly_white",
+        layout_updates={"paper_bgcolor": "rgb(1,2,3)", "plot_bgcolor": "rgb(4,5,6)"},
+    )
+    assert fig is not None
+    # Plotly expands the named template into a Template object (name not kept).
+    assert str(fig.layout.template) != str(fig_default.layout.template)
+    assert fig.layout.paper_bgcolor == "rgb(1,2,3)"
+    assert fig.layout.plot_bgcolor == "rgb(4,5,6)"
+
+
+@pytest.mark.essential
+def test_summary_height_per_panel():
+    pytest.importorskip("plotly", reason="plotting extras (batch) not installed")
+    from cellpy.plotting import theme
+    from cellpy.plotting.collected import summary_plotter
+
+    theme.make_collector_templates()
+    fig = summary_plotter(
+        _summary_frame(),
+        backend="plotly",
+        group_cells=False,
+        height_per_panel=180,
+        figure_border_height=40,
+        cols=1,
+    )
+    # 2 variables → 2 rows; height = border + rows * per_panel
+    assert fig.layout.height == 40 + 2 * 180
+
+
+@pytest.mark.essential
+def test_collected_plot_forwards_app_hooks():
+    pytest.importorskip("plotly", reason="plotting extras (batch) not installed")
+    from cellpy.plotting import theme
+    from cellpy.plotting.collected import collected_plot
+
+    theme.make_collector_templates()
+    fig = collected_plot(
+        _summary_frame(),
+        family_kind="summary",
+        backend="plotly",
+        group_cells=False,
+        plotly_template="plotly_white",
+        height_per_panel=150,
+        figure_border_height=50,
+        cols=1,
+        layout_updates={"margin": dict(l=10, r=10, t=10, b=10)},
+    )
+    assert fig is not None
+    assert fig.layout.height == 50 + 2 * 150
+    assert fig.layout.margin.l == 10
diff --git a/tests/test_collected_summary_axes.py b/tests/test_collected_summary_axes.py
index 4cd4f9d2..5e24518d 100644
--- a/tests/test_collected_summary_axes.py
+++ b/tests/test_collected_summary_axes.py
@@ -95,7 +95,7 @@ def test_summary_y_ranges_per_panel():
     pytest.importorskip("plotly", reason="plotting extras (batch) not installed")
     from cellpy.plotting import theme
     from cellpy.plotting.collected import (
-        _yaxis_key_for_facet_label,
+        _yaxis_key_for_variable,
         summary_plotter,
     )
 
@@ -107,8 +107,8 @@ def test_summary_y_ranges_per_panel():
         y_ranges={"coulombic_efficiency": [0, 110]},
     )
     assert fig is not None
-    ce_key = _yaxis_key_for_facet_label(fig, "variable=coulombic_efficiency")
-    cap_key = _yaxis_key_for_facet_label(fig, "variable=charge_capacity_gravimetric")
+    ce_key = _yaxis_key_for_variable(fig, "coulombic_efficiency")
+    cap_key = _yaxis_key_for_variable(fig, "charge_capacity_gravimetric")
     assert ce_key is not None
     assert cap_key is not None
     assert list(fig.layout[ce_key].range) == [0.0, 110.0]
@@ -122,7 +122,7 @@ def test_summary_y_ranges_forces_independent_when_share_y_true():
     pytest.importorskip("plotly", reason="plotting extras (batch) not installed")
     from cellpy.plotting import theme
     from cellpy.plotting.collected import (
-        _yaxis_key_for_facet_label,
+        _yaxis_key_for_variable,
         summary_plotter,
     )
 
@@ -136,7 +136,7 @@ def test_summary_y_ranges_forces_independent_when_share_y_true():
     )
     assert fig is not None
     assert fig.layout.yaxis2.matches in (None, False)
-    ce_key = _yaxis_key_for_facet_label(fig, "variable=coulombic_efficiency")
+    ce_key = _yaxis_key_for_variable(fig, "coulombic_efficiency")
     assert list(fig.layout[ce_key].range) == [0.0, 110.0]
 
 
@@ -145,7 +145,7 @@ def test_collected_plot_forwards_y_ranges():
     pytest.importorskip("plotly", reason="plotting extras (batch) not installed")
     from cellpy.plotting import theme
     from cellpy.plotting.collected import (
-        _yaxis_key_for_facet_label,
+        _yaxis_key_for_variable,
         collected_plot,
     )
 
@@ -158,5 +158,5 @@ def test_collected_plot_forwards_y_ranges():
         y_ranges={"coulombic_efficiency": [0.0, 110.0]},
     )
     assert fig is not None
-    ce_key = _yaxis_key_for_facet_label(fig, "variable=coulombic_efficiency")
+    ce_key = _yaxis_key_for_variable(fig, "coulombic_efficiency")
     assert list(fig.layout[ce_key].range) == [0.0, 110.0]