diff --git a/api/onnx_web/chain/base.py b/api/onnx_web/chain/base.py
index 7bfd49a5..63261d29 100644
--- a/api/onnx_web/chain/base.py
+++ b/api/onnx_web/chain/base.py
@@ -14,7 +14,7 @@ from ..utils import (
     ServerContext,
 )
 from .utils import (
-    process_tiles,
+    process_tile_grid,
 )
 
 logger = getLogger(__name__)
@@ -86,7 +86,7 @@ class ChainPipeline:
 
                     return tile
 
-                image = process_tiles(
+                image = process_tile_grid(
                     image, stage_params.tile_size, stage_params.outscale, [stage_tile])
             else:
                 logger.info('source image within tile size, running stage')
diff --git a/api/onnx_web/chain/blend_inpaint.py b/api/onnx_web/chain/blend_inpaint.py
index 5ed461db..8af082d6 100644
--- a/api/onnx_web/chain/blend_inpaint.py
+++ b/api/onnx_web/chain/blend_inpaint.py
@@ -27,7 +27,7 @@ from ..utils import (
     ServerContext,
 )
 from .utils import (
-    process_tiles,
+    process_tile_grid,
 )
 
 import numpy as np
@@ -98,7 +98,7 @@ def blend_inpaint(
         )
         return result.images[0]
 
-    output = process_tiles(source_image, SizeChart.auto, 1, [outpaint])
+    output = process_tile_grid(source_image, SizeChart.auto, 1, [outpaint])
 
     logger.info('final output image size', output.size)
     return output
diff --git a/api/onnx_web/chain/upscale_outpaint.py b/api/onnx_web/chain/upscale_outpaint.py
index f6957aa8..7712a976 100644
--- a/api/onnx_web/chain/upscale_outpaint.py
+++ b/api/onnx_web/chain/upscale_outpaint.py
@@ -27,7 +27,7 @@ from ..utils import (
     ServerContext,
 )
 from .utils import (
-    process_tiles,
+    process_tile_spiral,
 )
 
 import numpy as np
@@ -98,7 +98,7 @@ def upscale_outpaint(
         )
         return result.images[0]
 
-    output = process_tiles(source_image, SizeChart.auto, 1, [outpaint])
+    output = process_tile_spiral(source_image, SizeChart.auto, 1, [outpaint])
 
     logger.info('final output image size: %sx%s', output.width, output.height)
     return output
diff --git a/api/onnx_web/chain/utils.py b/api/onnx_web/chain/utils.py
index db98da3c..15119de1 100644
--- a/api/onnx_web/chain/utils.py
+++ b/api/onnx_web/chain/utils.py
@@ -10,7 +10,7 @@ class TileCallback(Protocol):
         pass
 
 
-def process_tiles(
+def process_tile_grid(
     source: Image.Image,
     tile: int,
     scale: int,
@@ -37,3 +37,47 @@ def process_tiles(
             image.paste(tile_image, (left * scale, top * scale))
 
     return image
+
+
+def process_tile_spiral(
+    source: Image.Image,
+    tile: int,
+    scale: int,
+    filters: List[TileCallback],
+    overlap: float = 0.5,
+) -> Image.Image:
+    if scale != 1:
+        raise Exception('unsupported scale')
+
+    width, height = source.size
+    image = Image.new('RGB', (width * scale, height * scale))
+    image.paste(source, (0, 0))
+
+    # TODO: only valid for overlap = 0.5
+    if overlap == 0.5:
+        tiles = [
+            (0, tile * -overlap),
+            (tile * overlap, tile * -overlap),
+            (tile * overlap, 0),
+            (tile * overlap, tile * overlap),
+            (0, tile * overlap),
+            (tile * -overlap, tile * -overlap),
+            (tile * -overlap, 0),
+            (tile * -overlap, tile * overlap),
+        ]
+
+    # tile tuples is source, multiply by scale for dest
+    counter = 0
+    for left, top in tiles:
+        logger.info('processing tile %s of %s', counter, len(tiles))
+        counter += 1
+
+        # TODO: only valid for scale == 1, resize source for others
+        tile_image = image.crop((left, top, left + tile, top + tile))
+
+        for filter in filters:
+            tile_image = filter(tile_image, (left, top, tile))
+
+        image.paste(tile_image, (left * scale, top * scale))
+
+    return image
diff --git a/api/onnx_web/utils.py b/api/onnx_web/utils.py
index 64c0be9d..cbd76208 100644
--- a/api/onnx_web/utils.py
+++ b/api/onnx_web/utils.py
@@ -97,15 +97,16 @@ def get_size(val: Union[int, str, None]) -> SizeChart:
     if val is None:
         return SizeChart.auto
 
-    if type(val) is str:
-        if val in SizeChart:
-            return SizeChart[val]
-        else:
-            return int(val)
-
     if type(val) is int:
         return val
 
+    if type(val) is str:
+        for size in SizeChart:
+            if val == size.name:
+                return size
+
+        return int(val)
+
     raise Exception('invalid size')
 
 
diff --git a/common/pipelines/example.json b/common/pipelines/example.json
index f059c599..547991e0 100644
--- a/common/pipelines/example.json
+++ b/common/pipelines/example.json
@@ -30,7 +30,7 @@
       "name": "save-local",
       "type": "persist-disk",
       "params": {
-        "tile_size": "8k"
+        "tile_size": "hd8k"
       }
     },
     {
@@ -40,7 +40,7 @@
         "bucket": "storage-stable-diffusion",
         "endpoint_url": "http://scylla.home.holdmyran.ch:8000",
         "profile_name": "ceph",
-        "tile_size": "8k"
+        "tile_size": "hd8k"
       }
     }
   ]