diff --git a/poetry.lock b/poetry.lock
index 64039295..4bd81499 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -770,4 +770,4 @@ files = [
 [metadata]
 lock-version = "2.0"
 python-versions = "^3.12"
-content-hash = "5a41028a2c142304569a38871947299dbbc88620051201dd804792da22638fa9"
+content-hash = "f7c434545c054dc9a2abdaaf8eb0b8a38b0ece4c7076af496739bc00d1d1fe22"
diff --git a/pyproject.toml b/pyproject.toml
index 2806276c..f51ceabb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -54,6 +54,7 @@ pytest-cov = "^6.0.0"
 pytest-html = "^4.1.1"
 allure-pytest = "^2.13.5"
 csv-diff = "^1.2"
+coverage = "^7.6.8"
 
 [tool.poetry.group.dev.dependencies]
 pylint = "^3.3.1"
@@ -63,3 +64,11 @@ licenseheaders = "^0.8.8"
 [build-system]
 requires = ["poetry-core"]
 build-backend = "poetry.core.masonry.api"
+
+[tool.pytest.ini_options]
+markers = [
+    "slow: marks tests as slow (deselect with '-m \"not slow\"')",
+    "serial",
+    "wip: mark tests as work-in-progress (delect with '-m \"not wip\"')",
+]
+
diff --git a/run_tests.sh b/run_tests.sh
index 902bfbdc..9a2ab2a5 100755
--- a/run_tests.sh
+++ b/run_tests.sh
@@ -25,27 +25,35 @@
 
 DIR=$(dirname -- $(realpath ${BASH_SOURCE}))
 
-export PYTHONPATH=$DIR/:$DIR/build/python:${PYTHONPATH}
+## export PYTHONPATH=$DIR/:$DIR/build/python:${PYTHONPATH}
 
-mkdir -p $DIR/build
+mkdir -p "$DIR"/build
 
-ALLURE_RESULTS_PATH=$DIR/build/allure-results
-ALLURE_REPORT_PATH=$DIR/build/allure-report
-COVERAGE_PATH=$DIR/build/coverage-results
+ALLURE_RESULTS_PATH="$DIR/build/allure-results"
+ALLURE_REPORT_PATH="$DIR/build/allure-report"
+COVERAGE_PATH="$DIR/build/coverage-results"
 
-poetry run pytest \
-	--alluredir $ALLURE_RESULTS_PATH \
-	--color no \
-	--cov=$COVERAGE_PATH \
-	--cov-report=html
+set -x
+set -e
+
+rm -rf "$ALLURE_RESULTS_PATH"
+rm -rf "$ALLURE_REPORT_PATH"
+rm -rf "$COVERAGE_PATH"
+
+poetry run coverage run -m pytest -m "not slow" \
+	--alluredir "$ALLURE_RESULTS_PATH" \
+	--color no
+
+poetry run coverage html --directory "$COVERAGE_PATH" 
 
 allure generate \
-	--single-file $ALLURE_RESULTS_PATH \
-	--output $ALLURE_REPORT_PATH \
+	--single-file "$ALLURE_RESULTS_PATH" \
+	--output "$ALLURE_REPORT_PATH" \
 	--clean
 
 if [[ -z "$RUNNER_OS" ]] && [[ -d "/Applications/Safari.app" ]]
 then
-    open -a Safari $ALLURE_REPORT_PATH/index.html
+    open -a Safari "$ALLURE_REPORT_PATH"/index.html
+    open -a Safari "$COVERAGE_PATH"/index.html
 fi
 
diff --git a/tests/rcx25/rcx25_test.py b/tests/rcx25/rcx25_test.py
index aba703b7..bf7a0f52 100644
--- a/tests/rcx25/rcx25_test.py
+++ b/tests/rcx25/rcx25_test.py
@@ -30,8 +30,8 @@
 import allure
 import csv_diff
 import os
+import pytest
 from typing import *
-import unittest
 
 import klayout.db as kdb
 import klayout.lay as klay
@@ -129,6 +129,7 @@ def assert_expected_matches_obtained(*path_components,
 
 @allure.parent_suite(parent_suite)
 @allure.tag(*tags)
+@pytest.mark.slow
 def test_single_plate_100um_x_100um_li1_over_substrate():
     # MAGIC GIVES (8.3 revision 485):
     #_______________________________ NOTE: with halo=8µm __________________________________
@@ -142,6 +143,8 @@ def test_single_plate_100um_x_100um_li1_over_substrate():
 
 @allure.parent_suite(parent_suite)
 @allure.tag(*tags)
+@pytest.mark.slow
+@pytest.mark.wip
 def test_overlap_plates_100um_x_100um_li1_m1():
     # MAGIC GIVES (8.3 revision 485):
     #_______________________________ NOTE: with halo=8µm __________________________________
@@ -164,6 +167,8 @@ def test_overlap_plates_100um_x_100um_li1_m1():
 
 @allure.parent_suite(parent_suite)
 @allure.tag(*tags)
+@pytest.mark.slow
+@pytest.mark.wip
 def test_overlap_plates_100um_x_100um_li1_m1_m2_m3():
     # MAGIC GIVES (8.3 revision 485): (sorting changed to match order)
     #_______________________________ NOTE: with halo=8µm __________________________________
@@ -203,6 +208,8 @@ def test_overlap_plates_100um_x_100um_li1_m1_m2_m3():
 
 @allure.parent_suite(parent_suite)
 @allure.tag(*tags)
+@pytest.mark.slow
+@pytest.mark.wip
 def test_sidewall_100um_x_100um_distance_200nm_li1():
     # MAGIC GIVES (8.3 revision 485): (sorting changed to match order)
     # _______________________________ NOTE: with halo=8µm __________________________________
@@ -227,6 +234,8 @@ def test_sidewall_100um_x_100um_distance_200nm_li1():
 
 @allure.parent_suite(parent_suite)
 @allure.tag(*tags)
+@pytest.mark.slow
+@pytest.mark.wip
 def test_sidewall_net_uturn_l1_redux():
     # MAGIC GIVES (8.3 revision 485): (sorting changed to match order)
     # _______________________________ NOTE: with halo=8µm __________________________________
@@ -247,6 +256,8 @@ def test_sidewall_net_uturn_l1_redux():
 
 @allure.parent_suite(parent_suite)
 @allure.tag(*tags)
+@pytest.mark.slow
+@pytest.mark.wip
 def test_sidewall_cap_vpp_04p4x04p6_l1_redux():
     # MAGIC GIVES (8.3 revision 485): (sorting changed to match order)
     # _______________________________ NOTE: with halo=8µm __________________________________
@@ -267,6 +278,8 @@ def test_sidewall_cap_vpp_04p4x04p6_l1_redux():
 
 @allure.parent_suite(parent_suite)
 @allure.tag(*tags)
+@pytest.mark.slow
+@pytest.mark.wip
 def test_near_body_shield_li1_m1():
     # MAGIC GIVES (8.3 revision 485): (sorting changed to match order)
     #_______________________________ NOTE: with halo=8µm __________________________________
@@ -292,6 +305,8 @@ def test_near_body_shield_li1_m1():
 
 @allure.parent_suite(parent_suite)
 @allure.tag(*tags)
+@pytest.mark.slow
+@pytest.mark.wip
 def test_sideoverlap_simple_plates_li1_m1():
     # MAGIC GIVES (8.3 revision 485): (sorting changed to match order)
     # _______________________________ NOTE: with halo=8µm __________________________________