diff --git a/test.py b/test.py
index 3f8b035..14f2cb1 100644
--- a/test.py
+++ b/test.py
@@ -11,41 +11,109 @@ def mm_to_pt(length):
     return (72.0 * length) / 25.4
 
 
+def _create_pdf(width, height):
+    return tmpfile
+
+
 @pytest.fixture(scope="module")
 def infile_a4_portrait():
-    doc = fitz.open()
-    width = mm_to_pt(210)
-    height = mm_to_pt(297)
-    page = doc.newPage(pno=-1, width=width, height=height)
-    img = page.newShape()
-
-    red = fitz.utils.getColor("red")
-    green = fitz.utils.getColor("green")
-    blue = fitz.utils.getColor("blue")
-    orange = fitz.utils.getColor("orange")
+    tmpfile = _create_pdf(mm_to_pt(210), mm_to_pt(297))
+    yield tmpfile
+    os.unlink(tmpfile)
 
-    img.insertText(fitz.Point(97, 620), "A", fontsize=600, color=blue)
-    img.commit()
-    img.drawLine(fitz.Point(0, 0), fitz.Point(width, height))
-    img.finish(color=red)
-    img.drawLine(fitz.Point(0, height), fitz.Point(width, 0))
-    img.finish(color=green)
-    img.drawRect(fitz.Rect(fitz.Point(0, 0), fitz.Point(width, height)))
-    img.finish(color=orange)
-    img.commit()
 
-    fd, tmpfile = tempfile.mkstemp(prefix="plakativ")
-    os.close(fd)
-    doc.save(tmpfile, pretty=True, expand=255)
+@pytest.fixture(scope="module")
+def infile_custom_portrait():
+    tmpfile = _create_pdf(mm_to_pt(200), mm_to_pt(400))
     yield tmpfile
     os.unlink(tmpfile)
 
 
 @pytest.fixture(scope="module")
 def infile_a4_landscape():
+    tmpfile = _create_pdf(mm_to_pt(297), mm_to_pt(210))
+    yield tmpfile
+    os.unlink(tmpfile)
+
+
+@pytest.fixture(scope="module")
+def infile_custom_landscape():
+    tmpfile = _create_pdf(mm_to_pt(400), mm_to_pt(200))
+    yield tmpfile
+    os.unlink(tmpfile)
+
+
+@pytest.fixture(scope="module")
+def infile_custom_square():
+    tmpfile = _create_pdf(mm_to_pt(300), mm_to_pt(300))
+    yield tmpfile
+    os.unlink(tmpfile)
+
+
+_formats = {
+    "dina4_portrait": (210, 297),
+    "dina4_landscape": (297, 210),
+    "dina3_portrait": (297, 420),
+    "dina3_landscape": (420, 297),
+}
+
+
+@pytest.mark.parametrize(
+    "postersize,input_pagesize,output_pagesize,expected",
+    [
+        (
+            _formats["dina3_portrait"],
+            _formats["dina4_portrait"],
+            None,
+            [
+                (
+                    ["0", "380.8549", "337.72779", "841.8898"],
+                    ["1.4141413", "0", "0", "1.4141413", "117.68077", "-538.5826"],
+                ),
+                (
+                    ["257.5478", "380.8549", "595.2756", "841.8898"],
+                    ["1.4141413", "0", "0", "1.4141413", "-364.20893", "-538.5826"],
+                ),
+                (
+                    ["0", "0", "337.72779", "461.03489"],
+                    ["1.4141413", "0", "0", "1.4141413", "117.68077", "189.9213"],
+                ),
+                (
+                    ["257.5478", "0", "595.2756", "461.03489"],
+                    ["1.4141413", "0", "0", "1.4141413", "-364.20893", "189.9213"],
+                ),
+            ],
+        ),
+        (
+            _formats["dina3_landscape"],
+            _formats["dina4_landscape"],
+            None,
+            [
+                (
+                    ["0", "257.5478", "461.03489", "595.2756"],
+                    ["1.4141413", "0", "0", "1.4141413", "189.9213", "-364.20893"],
+                ),
+                (
+                    ["380.8549", "257.5478", "841.8898", "595.2756"],
+                    ["1.4141413", "0", "0", "1.4141413", "-538.5826", "-364.20893"],
+                ),
+                (
+                    ["0", "0", "461.03489", "337.72779"],
+                    ["1.4141413", "0", "0", "1.4141413", "189.9213", "117.68074"],
+                ),
+                (
+                    ["380.8549", "0", "841.8898", "337.72779"],
+                    ["1.4141413", "0", "0", "1.4141413", "-538.5826", "117.68074"],
+                ),
+            ],
+        ),
+    ],
+)
+def test_cases(postersize, input_pagesize, output_pagesize, expected):
+    width = mm_to_pt(input_pagesize[0])
+    height = mm_to_pt(input_pagesize[1])
+
     doc = fitz.open()
-    width = mm_to_pt(297)
-    height = mm_to_pt(210)
     page = doc.newPage(pno=-1, width=width, height=height)
     img = page.newShape()
 
@@ -64,139 +132,23 @@ def infile_a4_landscape():
     img.finish(color=orange)
     img.commit()
 
-    fd, tmpfile = tempfile.mkstemp(prefix="plakativ")
+    fd, infile = tempfile.mkstemp(
+        prefix="plakativ", suffix="%f_%f.pdf" % (width, height)
+    )
     os.close(fd)
-    doc.save(tmpfile, pretty=True, expand=255)
-    yield tmpfile
-    os.unlink(tmpfile)
-
+    doc.save(infile, pretty=True, expand=255)
 
-def test_foo_a3_portrait(infile_a4_portrait):
     fd, outfile = tempfile.mkstemp(prefix="plakativ")
     os.close(fd)
-    plakativ.compute_layout(infile_a4_portrait, outfile, mode="size", size=(297, 420))
+    plakativ.compute_layout(infile, outfile, mode="size", size=postersize)
+    os.unlink(infile)
 
     reader = pdfrw.PdfReader(outfile)
     os.unlink(outfile)
 
     pages = reader.Root.Pages.Kids
-    assert len(pages) == 4
-    assert pages[0].Resources.XObject.fzFrm0.BBox == [
-        "0",
-        "380.8549",
-        "337.72779",
-        "841.8898",
-    ]
-    assert pages[1].Resources.XObject.fzFrm0.BBox == [
-        "257.5478",
-        "380.8549",
-        "595.2756",
-        "841.8898",
-    ]
-    assert pages[2].Resources.XObject.fzFrm0.BBox == [
-        "0",
-        "0",
-        "337.72779",
-        "461.03489",
-    ]
-    assert pages[3].Resources.XObject.fzFrm0.BBox == [
-        "257.5478",
-        "0",
-        "595.2756",
-        "461.03489",
-    ]
-    assert pages[0].Resources.XObject.fzFrm0.Matrix == [
-        "1.4141413",
-        "0",
-        "0",
-        "1.4141413",
-        "117.68077",
-        "-538.5826",
-    ]
-    assert pages[1].Resources.XObject.fzFrm0.Matrix == [
-        "1.4141413",
-        "0",
-        "0",
-        "1.4141413",
-        "-364.20893",
-        "-538.5826",
-    ]
-    assert pages[2].Resources.XObject.fzFrm0.Matrix == [
-        "1.4141413",
-        "0",
-        "0",
-        "1.4141413",
-        "117.68077",
-        "189.9213",
-    ]
-    assert pages[3].Resources.XObject.fzFrm0.Matrix == [
-        "1.4141413",
-        "0",
-        "0",
-        "1.4141413",
-        "-364.20893",
-        "189.9213",
-    ]
-
-
-def test_foo_a3_landscape(infile_a4_landscape):
-    fd, outfile = tempfile.mkstemp(prefix="plakativ")
-    os.close(fd)
-    plakativ.compute_layout(infile_a4_landscape, outfile, mode="size", size=(420, 296))
+    assert len(pages) == len(expected)
 
-    reader = pdfrw.PdfReader(outfile)
-    os.unlink(outfile)
-
-    pages = reader.Root.Pages.Kids
-    assert len(pages) == 4
-    assert pages[0].Resources.XObject.fzFrm0.BBox == [
-        "0",
-        "257.41648",
-        "461.1662",
-        "595.2756",
-    ]
-    assert pages[1].Resources.XObject.fzFrm0.BBox == [
-        "380.72358",
-        "257.41648",
-        "841.8898",
-        "595.2756",
-    ]
-    assert pages[2].Resources.XObject.fzFrm0.BBox == ["0", "0", "461.1662", "337.8591"]
-    assert pages[3].Resources.XObject.fzFrm0.BBox == [
-        "380.72358",
-        "0",
-        "841.8898",
-        "337.8591",
-    ]
-    assert pages[0].Resources.XObject.fzFrm0.Matrix == [
-        "1.4095239",
-        "0",
-        "0",
-        "1.4095239",
-        "191.86499",
-        "-362.83467",
-    ]
-    assert pages[1].Resources.XObject.fzFrm0.Matrix == [
-        "1.4095239",
-        "0",
-        "0",
-        "1.4095239",
-        "-536.6389",
-        "-362.83467",
-    ]
-    assert pages[2].Resources.XObject.fzFrm0.Matrix == [
-        "1.4095239",
-        "0",
-        "0",
-        "1.4095239",
-        "191.86499",
-        "119.055118",
-    ]
-    assert pages[3].Resources.XObject.fzFrm0.Matrix == [
-        "1.4095239",
-        "0",
-        "0",
-        "1.4095239",
-        "-536.6389",
-        "119.055118",
-    ]
+    for page, (bbox, matrix) in zip(pages, expected):
+        assert page.Resources.XObject.fzFrm0.BBox == bbox
+        assert page.Resources.XObject.fzFrm0.Matrix == matrix