diff --git a/plugins/printers/api/asset_routes.py b/plugins/printers/api/asset_routes.py
index 46813f00..da463726 100644
--- a/plugins/printers/api/asset_routes.py
+++ b/plugins/printers/api/asset_routes.py
@@ -2129,9 +2129,14 @@ def _get_low_supplies_data():
     # dashboard then showed Low Supplies 0 while the monitoring was dead, which
     # is not a missing feature but a wrong statement: it reads as reassurance.
     if not service.isconfigured:
-        return {'printers': [], 'unavailable': 'Supply monitoring is not configured',
-                'summary': {'total_checked': 0, 'low': 0, 'critical': 0}}
+        # Enabled plus a URL plus a token. Absent any of those the site has not
+        # asked for supply monitoring, and a permanent "not configured" line
+        # would be a card reporting nothing wrong every day - which is how a
+        # board teaches people to stop reading it. Nothing to say: stay hidden.
+        return {'printers': [], 'summary': {'total_checked': 0, 'low': 0, 'critical': 0}}
     if not service.isreachable:
+        # Configured and unanswerable is a different thing: something meant to
+        # work is not working, and the cartridges are NOT known to be fine.
         return {'printers': [], 'unavailable': 'Supply monitoring is not reachable',
                 'summary': {'total_checked': 0, 'low': 0, 'critical': 0}}
 
diff --git a/tests/test_plugins/test_supplies_card_blindness.py b/tests/test_plugins/test_supplies_card_blindness.py
new file mode 100644
index 00000000..1e766a24
--- /dev/null
+++ b/tests/test_plugins/test_supplies_card_blindness.py
@@ -0,0 +1,90 @@
+"""The supplies dashboard card must not report "nothing low" when it cannot see.
+
+_get_low_supplies_data returned the same empty result for three different
+situations - Zabbix not configured, Zabbix unreachable, and every cartridge
+full - so the dashboard displayed "Low Supplies 0 / Critical 0" while the
+monitoring was dead. That is not a missing feature; it is a wrong statement, and
+it reads as reassurance.
+
+These pin the three cases apart.
+"""
+from unittest.mock import patch
+
+import pytest
+
+from shopdb.api import db
+from shopdb.core.models import Setting
+
+
+def _call(client, auth_headers):
+    response = client.get('/api/printers/dashboard/supplies', headers=auth_headers)
+    assert response.status_code == 200
+    return response.get_json()['data']
+
+
+class FakeService:
+    def __init__(self, configured, reachable):
+        self.isconfigured = configured
+        self.isreachable = reachable
+
+
+@pytest.fixture(autouse=True)
+def _clear_cache(app):
+    from shopdb.extensions import cache
+    cache.delete('printers_low_supplies')
+    yield
+    cache.delete('printers_low_supplies')
+
+
+def test_unreachable_says_so_rather_than_reporting_zero(client, auth_headers):
+    """Configured and unanswerable: the cartridges are NOT known to be fine."""
+    with patch('plugins.printers.api.asset_routes.ZabbixService',
+               return_value=FakeService(configured=True, reachable=False)):
+        data = _call(client, auth_headers)
+
+    assert data['rows'] == []
+    assert data['unavailable'] == 'Supply monitoring is not reachable'
+
+
+def test_unconfigured_stays_quiet(client, auth_headers):
+    """The site did not ask for supply monitoring.
+
+    A permanent "not configured" line would be a card reporting nothing wrong
+    every day, which is how a board teaches people to stop reading it. It has
+    nothing to say, so it says nothing and the card hides.
+    """
+    with patch('plugins.printers.api.asset_routes.ZabbixService',
+               return_value=FakeService(configured=False, reachable=False)):
+        data = _call(client, auth_headers)
+
+    assert data['rows'] == []
+    assert data.get('unavailable') is None
+
+
+def test_reachable_with_nothing_low_is_not_flagged_as_blind(client, auth_headers):
+    """Zabbix answered and every cartridge is fine. That is a real zero."""
+    with patch('plugins.printers.api.asset_routes._get_low_supplies_data',
+               return_value={'printers': [],
+                             'summary': {'total_checked': 3, 'low': 0, 'critical': 0}}):
+        data = _call(client, auth_headers)
+
+    assert data['rows'] == []
+    assert data.get('unavailable') is None
+
+
+def test_the_envelope_carries_rows_so_the_card_can_still_render(client, auth_headers):
+    """The response became an envelope to carry the reason; rows must survive."""
+    printer = {
+        'printerid': 1, 'assetnumber': 'PRN-1', 'printername': 'Front office',
+        'location': 'Bay 3', 'mapx': None, 'mapy': None, 'levelid': None,
+        'supplies': [{'name': 'Black', 'remaining': 2, 'status': 'critical'}],
+    }
+    with patch('plugins.printers.api.asset_routes._get_low_supplies_data',
+               return_value={'printers': [printer],
+                             'summary': {'total_checked': 1, 'low': 1, 'critical': 1}}):
+        data = _call(client, auth_headers)
+
+    assert data.get('unavailable') is None
+    assert len(data['rows']) == 1
+    assert data['rows'][0]['printername'] == 'Front office'
+    assert data['rows'][0]['iscritical'] is True