diff --git a/polymerist/genutils/typetools.py b/polymerist/genutils/typetools.py
deleted file mode 100644
index 44f75a7..0000000
--- a/polymerist/genutils/typetools.py
+++ /dev/null
@@ -1,50 +0,0 @@
-'''Additional type-hinting and typechecking not provided by builtins'''
-
-from typing import Any, Callable, ParamSpec, TypeAlias, TypeVar, Union
-import numpy.typing # NOTE : this import is necessary to use np.typing calls
-import numpy as np
-
-
-# GENERIC TYPE VARIABLES
-T = TypeVar('T') # universal generic type
-
-C = TypeVar('C') # generic type for a class
-O = TypeVar('O') # generic type for an object passed to a function
-F = TypeVar('F') # generic type for a function
-U = TypeVar('U') # generic class from representing Literal Unions (since arg-free union is not supported)
-
-P = ParamSpec('P') # for representing (preserved) input parameters
-R = TypeVar('R')   # for representing generic return values
-
-Args   = TypeVar('Args'  ) # generic type for arguments to a function
-KWArgs = TypeVar('KWArgs') # generic type for keyword arguments to a function
-
-# CATEGORICAL TYPEHINTS
-def _union_member_factory(union : U) -> Callable[[Any], bool]:
-    '''Factory for making Uion-membership-checking functions'''
-    def isinunion(var : Any) -> bool:
-        '''Check if an object is a member of a Union class'''
-        return isinstance(var, union.__args__)
-    return isinunion
-
-Numeric = Union[int, float, complex, np.number]
-ArrayLike = Union[list, tuple, np.ndarray, np.typing.ArrayLike] # exclude dicts and sets, as they introduce complicated behaviors
-JSONSerializable = Union[str, bool, int, float, tuple, list, dict] 
-
-isnumeric = _union_member_factory(Numeric)
-isarraylike = _union_member_factory(ArrayLike)
-isjsonserializable = _union_member_factory(JSONSerializable)
-
-# NUMPY-SPECIFIC TYPEHINTS
-N = TypeVar('N', bound=int) # for typing arbitrary array dimension
-M = TypeVar('M', bound=int) # for typing arbitrary array dimension
-DType = TypeVar('DType', bound=np.generic)
-Shape : TypeAlias = tuple
-
-Coords2D : TypeAlias = np.ndarray[Shape[M, 2], DType] # an Mx2 array of M 3D coordinates
-Coords3D : TypeAlias = np.ndarray[Shape[M, 3], DType] # an Mx3 array of M 3D coordinates
-CoordsND : TypeAlias = np.ndarray[Shape[M, N], DType] # an MxN array of M ND coordinates
-
-Vector2D : TypeAlias = np.ndarray[Shape[2], DType] # a 1x2 array of M 3D coordinates
-Vector3D : TypeAlias = np.ndarray[Shape[3], DType] # a 1x3 array of M 3D coordinates
-VectorND : TypeAlias = np.ndarray[Shape[N], DType] # a 1xN array of M ND coordinates
\ No newline at end of file
diff --git a/polymerist/genutils/typetools/__init__.py b/polymerist/genutils/typetools/__init__.py
new file mode 100644
index 0000000..d22eb0a
--- /dev/null
+++ b/polymerist/genutils/typetools/__init__.py
@@ -0,0 +1 @@
+'''Additional type-hinting and typechecking not provided by Python builtins'''
\ No newline at end of file
diff --git a/polymerist/genutils/typetools/categorical.py b/polymerist/genutils/typetools/categorical.py
new file mode 100644
index 0000000..e47b2ae
--- /dev/null
+++ b/polymerist/genutils/typetools/categorical.py
@@ -0,0 +1,22 @@
+'''Type-hinting for Union-bound categories of types'''
+
+from typing import Any, Callable, Literal, Type, Union
+from numpy import number as np_number
+from numpy.typing import ArrayLike
+
+from .parametric import U
+
+
+def _union_member_factory(union : U) -> Callable[[Any], bool]:
+    '''Factory for making Uion-membership-checking functions'''
+    def isinunion(var : Any) -> bool:
+        '''Check if an object is a member of a Union class'''
+        return isinstance(var, union.__args__)
+    return isinunion
+
+Numeric = Union[int, float, complex, np_number]
+JSONSerializable = Union[str, bool, int, float, tuple, list, dict] 
+
+isnumeric = _union_member_factory(Numeric)
+isarraylike = _union_member_factory(ArrayLike)
+isjsonserializable = _union_member_factory(JSONSerializable)
\ No newline at end of file
diff --git a/polymerist/genutils/typetools/numpytypes.py b/polymerist/genutils/typetools/numpytypes.py
new file mode 100644
index 0000000..2032aba
--- /dev/null
+++ b/polymerist/genutils/typetools/numpytypes.py
@@ -0,0 +1,19 @@
+'''Type aliases specific to numpy arrays'''
+
+from typing import TypeAlias, TypeVar
+import numpy as np
+import numpy.typing as npt
+
+
+N = TypeVar('N', bound=int) # for typing arbitrary array dimension
+M = TypeVar('M', bound=int) # for typing arbitrary array dimension
+DType = TypeVar('DType', bound=np.generic)
+Shape : TypeAlias = tuple
+
+Coords2D : TypeAlias = np.ndarray[Shape[M, 2], DType] # an Mx2 array of M 3D coordinates
+Coords3D : TypeAlias = np.ndarray[Shape[M, 3], DType] # an Mx3 array of M 3D coordinates
+CoordsND : TypeAlias = np.ndarray[Shape[M, N], DType] # an MxN array of M ND coordinates
+
+Vector2D : TypeAlias = np.ndarray[Shape[2], DType] # a 1x2 array of M 3D coordinates
+Vector3D : TypeAlias = np.ndarray[Shape[3], DType] # a 1x3 array of M 3D coordinates
+VectorND : TypeAlias = np.ndarray[Shape[N], DType] # a 1xN array of M ND coordinates
\ No newline at end of file
diff --git a/polymerist/genutils/typetools/parametric.py b/polymerist/genutils/typetools/parametric.py
new file mode 100644
index 0000000..3fef8d1
--- /dev/null
+++ b/polymerist/genutils/typetools/parametric.py
@@ -0,0 +1,17 @@
+'''Type aliases for Python callable input parameters'''
+
+from typing import TypeVar, ParamSpec, _UnionGenericAlias
+
+T = TypeVar('T') # universal generic type
+
+C = TypeVar('C') # generic type for a class
+O = TypeVar('O') # generic type for an object passed to a function
+F = TypeVar('F') # generic type for a function
+U = TypeVar('U', bound=_UnionGenericAlias) # generic class from representing Literal Unions (since arg-free union is not supported)
+
+P = ParamSpec('P') # for representing (preserved) input parameters
+R = TypeVar('R')   # for representing generic return values
+
+# TOSELF: replace with typing.ParamSpecArgs/.ParamSpecKWArgs?
+Args   = TypeVar('Args'  ) # generic type for arguments to a function
+KWArgs = TypeVar('KWArgs') # generic type for keyword arguments to a function