diff --git a/.vscode/settings.json b/.vscode/settings.json
index b7e254a5..391bbf6c 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -2,5 +2,4 @@
     "python.linting.pylintEnabled": false,
     "python.linting.flake8Enabled": true,
     "python.linting.enabled": true,
-    "python.pythonPath": "C:\\Users\\joburger\\Anaconda3\\envs\\compas_slicer\\python.exe"
 }
\ No newline at end of file
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 31297d8b..763d69d4 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -11,14 +11,16 @@ Unreleased
 
 **Added**
 * Output nested printpoints  
+* Added reverse_open_paths argument to seams_align to control if the direction of open paths should be reversed or not. Defaults to False.
+* Added reverse_open_paths argument to sort_paths_minimum_travel_time to control if the direction of open paths should be reversed or not. Defaults to False.
 
 **Changed**
-* Updates in the visualization of PrintPoints
-* Added seams_align(next_path) to the standard planar slicing routine
-* Added unify_path_orientation back into the standard planar slicing routine
-
+* Updates in the visualization of PrintPoints.
+* Added seams_align(next_path) to the standard planar slicing routine.
+* Added unify_path_orientation back into the standard planar slicing routine.
 
 **Fixed**
+* Changed unify_path_orientation to only work for closed paths.
 
 **Deprecated**
 
diff --git a/src/compas_slicer/geometry/print_point.py b/src/compas_slicer/geometry/print_point.py
index 17d68170..5f04eab1 100644
--- a/src/compas_slicer/geometry/print_point.py
+++ b/src/compas_slicer/geometry/print_point.py
@@ -42,6 +42,10 @@ def __init__(self, pt, layer_height, mesh_normal):
         self.pt = pt
         self.layer_height = layer_height
 
+        # --- layer, path index attributes
+        self.layer_index = None
+        self.path_index = None
+
         self.mesh_normal = mesh_normal  # compas.geometry.Vector
         self.up_vector = Vector(0, 0, 1)  # default value that can be updated
         self.frame = self.get_frame()  # compas.geometry.Frame
@@ -90,6 +94,9 @@ def to_data(self):
             'point': [self.pt[0], self.pt[1], self.pt[2]],
             'layer_height': self.layer_height,
 
+            'layer_index': self.layer_index,
+            'path_index': self.path_index,
+
             'mesh_normal': self.mesh_normal.to_data(),
             'up_vector': self.up_vector.to_data(),
             'frame': self.frame.to_data(),
diff --git a/src/compas_slicer/post_processing/seams_align.py b/src/compas_slicer/post_processing/seams_align.py
index d5063d0a..21a115e4 100644
--- a/src/compas_slicer/post_processing/seams_align.py
+++ b/src/compas_slicer/post_processing/seams_align.py
@@ -8,7 +8,7 @@
 __all__ = ['seams_align']
 
 
-def seams_align(slicer, align_with="next_path"):
+def seams_align(slicer, align_with="next_path", reverse_open_paths=False):
     """Aligns the seams (start- and endpoint) of a print.
 
     Parameters
@@ -22,6 +22,8 @@ def seams_align(slicer, align_with="next_path"):
         x_axis       = orients the seam to the x_axis
         y_axis       = orients the seam to the y_axis
         Point(x,y,z) = orients the seam according to the given point
+    reverse_open_paths: bool (defaults to False)
+        Boolean toggle whether to reverse the direction of open paths or not.
 
     Returns
     -------
@@ -39,24 +41,23 @@ def seams_align(slicer, align_with="next_path"):
                 #  determines the correct point to align the current path with
                 if len(layer.paths) == 1 and i == 0:
                     #  if ONE PATH and FIRST LAYER
-                    #  >>> align with second layer
-                    pt_to_align_with = slicer.layers[i + 1].paths[0].points[0]
+                    #  >>> align with first point of first layer (no change)
+                    pt_to_align_with = slicer.layers[0].paths[0].points[0]
                 if len(layer.paths) == 1 and i != 0:
-                    last_path_index = len(slicer.layers[i - 1].paths) - 1
                     #  if ONE PATH and NOT FIRST LAYER
-                    #  >>> align with previous layer
-                    pt_to_align_with = slicer.layers[i - 1].paths[last_path_index].points[-1]
+                    #  >>> align with last point of previous layer
+                    pt_to_align_with = slicer.layers[i - 1].paths[0].points[-1]
                 if len(layer.paths) != 1 and i == 0 and j == 0:
                     #  if MULTIPLE PATHS and FIRST LAYER and FIRST PATH
-                    #  >>> align with second path of first layer
+                    #  >>> align with last point of next path of first layer
                     pt_to_align_with = slicer.layers[i].paths[i + 1].points[-1]
                 if len(layer.paths) != 1 and j != 0:
                     #  if MULTIPLE PATHS and NOT FIRST PATH
-                    #  >>> align with previous path
+                    #  >>> align with last point of previous path
                     pt_to_align_with = slicer.layers[i].paths[j - 1].points[-1]
                 if len(layer.paths) != 1 and i != 0 and j == 0:
-                    #  if MULTIPLE PATHS and NOT FIRST LAYER and FIRST PATH
-                    #  >>> align with first path of previous layer
+                    #  if MULTIPLE PATHS and NOT FIRST LAYER and NOT FIRST PATH
+                    #  >>> align with last point of previous path of previous layer
                     last_path_index = len(slicer.layers[i - 1].paths) - 1
                     pt_to_align_with = slicer.layers[i - 1].paths[last_path_index].points[-1]
 
@@ -74,7 +75,7 @@ def seams_align(slicer, align_with="next_path"):
             # CLOSED PATHS
             if path.is_closed:
                 #  get the points of the current layer and path
-                path_to_change = layer.paths[j].points
+                path_to_change = path.points
 
                 # check if start- and end-points are the same point
                 if path_to_change[0] == path_to_change[-1]:
@@ -94,11 +95,11 @@ def seams_align(slicer, align_with="next_path"):
                 if first_last_point_the_same:
                     shift_list = shift_list + [shift_list[0]]
 
-                layer.paths[j].points = shift_list
+                path.points = shift_list
 
             else:
                 # OPEN PATHS
-                path_to_change = layer.paths[j].points
+                path_to_change = path.points
 
                 # get the distance between the align point and the start/end point
                 start = path_to_change[0]
@@ -107,8 +108,9 @@ def seams_align(slicer, align_with="next_path"):
                 d_end = distance_point_point(end, pt_to_align_with)
 
                 # if closer to end point > reverse list
-                if d_start > d_end:
-                    layer.paths[j].points.reverse()
+                if reverse_open_paths:
+                    if d_start > d_end:
+                        path.points.reverse()
 
 
 if __name__ == "__main__":
diff --git a/src/compas_slicer/post_processing/simplify_paths_rdp.py b/src/compas_slicer/post_processing/simplify_paths_rdp.py
index 8d3937af..212d8d63 100644
--- a/src/compas_slicer/post_processing/simplify_paths_rdp.py
+++ b/src/compas_slicer/post_processing/simplify_paths_rdp.py
@@ -3,13 +3,8 @@
 import logging
 import progressbar
 from compas.geometry import Point
-import compas_slicer.utilities as utils
 from compas.plugins import PluginNotInstalledError
 
-packages = utils.TerminalCommand('conda list').get_split_output_strings()
-if 'igl' in packages:
-    import igl
-
 logger = logging.getLogger('logger')
 
 __all__ = ['simplify_paths_rdp',
@@ -55,7 +50,7 @@ def simplify_paths_rdp_igl(slicer, threshold):
         Low threshold removes few points, high threshold removes many points.
     """
     try:
-        utils.check_package_is_installed('igl')
+        import igl
         logger.info("Paths simplification rdp - igl")
         remaining_pts_num = 0
 
diff --git a/src/compas_slicer/post_processing/sort_paths_minimum_travel_time.py b/src/compas_slicer/post_processing/sort_paths_minimum_travel_time.py
index 50f15a5b..9dc7a865 100644
--- a/src/compas_slicer/post_processing/sort_paths_minimum_travel_time.py
+++ b/src/compas_slicer/post_processing/sort_paths_minimum_travel_time.py
@@ -8,13 +8,15 @@
 __all__ = ['sort_paths_minimum_travel_time']
 
 
-def sort_paths_minimum_travel_time(slicer):
+def sort_paths_minimum_travel_time(slicer, reverse_open_paths=False):
     """Sorts the paths within a horizontal layer to reduce total travel time.
 
     Parameters
     ----------
     slicer: :class:`compas_slicer.slicers.BaseSlicer`
         An instance of one of the compas_slicer.slicers classes.
+    reverse_open_paths: bool (defaults to False)
+        Boolean toggle whether to reverse the direction of open paths or not.
     """
     logger.info("Sorting contours to minimize travel time")
 
@@ -23,7 +25,7 @@ def sort_paths_minimum_travel_time(slicer):
     for i, layer in enumerate(slicer.layers):
         sorted_paths = []
         while len(layer.paths) > 0:
-            index = closest_path(ref_point, layer.paths)  # find the closest path to the reference point
+            index = closest_path(ref_point, layer.paths, reverse_open_paths)  # find the closest path to the reference point
             sorted_paths.append(layer.paths[index])  # add the closest path to the sorted list
             ref_point = layer.paths[index].points[-1]
             layer.paths.pop(index)
@@ -31,7 +33,7 @@ def sort_paths_minimum_travel_time(slicer):
         slicer.layers[i].paths = sorted_paths
 
 
-def adjust_seam_to_closest_pos(ref_point, path):
+def adjust_seam_to_closest_pos(ref_point, path, reverse_open_paths):
     """Aligns the seam (start- and endpoint) of a contour so that it is closest to a given point.
     for open paths, check if the end point closest to the reference point is the start point
 
@@ -57,11 +59,12 @@ def adjust_seam_to_closest_pos(ref_point, path):
         path.points = adjusted_seam
     else:  # if path is open
         #  if end point is closer than start point >> flip
-        if distance_point_point(ref_point, path.points[0]) > distance_point_point(ref_point, path.points[-1]):
-            path.points.reverse()
+        if reverse_open_paths:
+            if distance_point_point(ref_point, path.points[0]) > distance_point_point(ref_point, path.points[-1]):
+                path.points.reverse()
 
 
-def closest_path(ref_point, somepaths):
+def closest_path(ref_point, somepaths, reverse_open_paths):
     """Finds the closest path to a reference point in a list of paths.
 
     Parameters
@@ -74,7 +77,7 @@ def closest_path(ref_point, somepaths):
 
     for i, path in enumerate(somepaths):
         #  for each path, adjust the seam to be in the closest vertex to ref_point
-        adjust_seam_to_closest_pos(ref_point, path)
+        adjust_seam_to_closest_pos(ref_point, path, reverse_open_paths)
         #  calculate the minimum distance to the nearest seam of each path
         min_dist_temp = distance_point_point(ref_point, path.points[0])
         if min_dist_temp < min_dist:
diff --git a/src/compas_slicer/post_processing/unify_paths_orientation.py b/src/compas_slicer/post_processing/unify_paths_orientation.py
index d0bbb84b..fa830651 100644
--- a/src/compas_slicer/post_processing/unify_paths_orientation.py
+++ b/src/compas_slicer/post_processing/unify_paths_orientation.py
@@ -19,14 +19,15 @@ def unify_paths_orientation(slicer):
 
     for i, layer in enumerate(slicer.layers):
         for j, path in enumerate(layer.paths):
-            reference_points = None  # find reference points for each path, if possible
-            if j > 0:
-                reference_points = layer.paths[0].points
-            elif i > 0 and j == 0:
-                reference_points = slicer.layers[i - 1].paths[0].points
-
-            if reference_points:  # then reorient current pts based on reference
-                path.points = match_paths_orientations(path.points, reference_points, path.is_closed)
+            if path.is_closed:
+                reference_points = None  # find reference points for each path, if possible
+                if j > 0:
+                    reference_points = layer.paths[0].points
+                elif i > 0 and j == 0:
+                    reference_points = slicer.layers[i - 1].paths[0].points
+
+                if reference_points:  # then reorient current pts based on reference
+                    path.points = match_paths_orientations(path.points, reference_points, path.is_closed)
 
 
 def match_paths_orientations(pts, reference_points, is_closed):
diff --git a/src/compas_slicer/print_organization/planar_print_organizer.py b/src/compas_slicer/print_organization/planar_print_organizer.py
index cb37689b..4bbd32d7 100644
--- a/src/compas_slicer/print_organization/planar_print_organizer.py
+++ b/src/compas_slicer/print_organization/planar_print_organizer.py
@@ -60,6 +60,9 @@ def create_printpoints(self, generate_mesh_normals=True):
                         n = normals[count] if generate_mesh_normals else Vector(0, 0, 1)
                         printpoint = PrintPoint(pt=point, layer_height=self.slicer.layer_height, mesh_normal=n)
 
+                        printpoint.layer_index = i
+                        printpoint.path_index = j
+
                         self.printpoints_dict['layer_%d' % i]['path_%d' % j].append(printpoint)
                         bar.update(count)
                         count += 1
diff --git a/src/compas_slicer/slicers/planar_slicing/planar_slicing_cgal.py b/src/compas_slicer/slicers/planar_slicing/planar_slicing_cgal.py
index baee5d57..d15fbeaf 100644
--- a/src/compas_slicer/slicers/planar_slicing/planar_slicing_cgal.py
+++ b/src/compas_slicer/slicers/planar_slicing/planar_slicing_cgal.py
@@ -4,7 +4,6 @@
 from compas_slicer.geometry import Path
 import progressbar
 import logging
-import compas_slicer.utilities as utils
 from compas.plugins import PluginNotInstalledError
 
 logger = logging.getLogger('logger')
@@ -21,11 +20,10 @@ def create_planar_paths_cgal(mesh, planes):
         A compas mesh.
     planes: list, :class: 'compas.geometry.Plane'
     """
-    packages = utils.TerminalCommand('conda list').get_split_output_strings()
 
-    if 'compas-cgal' in packages or 'compas_cgal' in packages:
+    try:
         from compas_cgal.slicer import slice_mesh
-    else:
+    except Exception:
         raise PluginNotInstalledError("--------ATTENTION! ----------- \
                         Compas_cgal library is missing! \
                         You can't use this planar slicing method without it. \