diff --git a/libj2dplot/code/J2DPlotFunctionBase.cpp b/libj2dplot/code/J2DPlotFunctionBase.cpp
index 04f4870fe..066d39227 100644
--- a/libj2dplot/code/J2DPlotFunctionBase.cpp
+++ b/libj2dplot/code/J2DPlotFunctionBase.cpp
@@ -12,6 +12,8 @@
 #include <jx-af/jcore/JMinMax.h>
 #include <jx-af/jcore/jAssert.h>
 
+const JSize kDefSampleCount = 100;	// # of points for approximating y range
+
 /*********************************************************************************
  Constructor
 
@@ -31,7 +33,7 @@ J2DPlotFunctionBase::J2DPlotFunctionBase
 	itsXMin = JMin(xMin, xMax);
 	itsXMax = JMax(xMin, xMax);
 
-	itsValues = jnew JArray<Point>(7);
+	itsValues = jnew JArray<Point>(kDefSampleCount);
 	ListenTo(itsPlot);
 }
 
@@ -109,8 +111,7 @@ J2DPlotFunctionBase::GetYRange
 	const
 {
 	const JSize pointCount = itsPlot->GetSmoothSteps();
-	JArray<Point> list;
-	list.SetMinSize(pointCount);
+	JArray<Point> list(pointCount);
 	EvaluateFunction(xMin, xMax, xLinear, pointCount, &list);
 
 	*yMin = *yMax = 0.0;
diff --git a/libj2dplot/code/J2DVectorData.cpp b/libj2dplot/code/J2DVectorData.cpp
index 7c92eec8a..bd9548036 100644
--- a/libj2dplot/code/J2DVectorData.cpp
+++ b/libj2dplot/code/J2DVectorData.cpp
@@ -11,6 +11,8 @@
 #include <jx-af/jcore/JMinMax.h>
 #include <jx-af/jcore/jAssert.h>
 
+const JSize kDefSampleCount = 100;
+
 /*********************************************************************************
  Constructor function (static)
 
@@ -69,10 +71,10 @@ J2DVectorData::J2DVectorData()
 {
 	J2DVectorDataX();
 
-	itsXData  = jnew JArray<JFloat>(7);
-	itsYData  = jnew JArray<JFloat>(7);
-	itsVXData = jnew JArray<JFloat>(7);
-	itsVYData = jnew JArray<JFloat>(7);
+	itsXData  = jnew JArray<JFloat>(kDefSampleCount);
+	itsYData  = jnew JArray<JFloat>(kDefSampleCount);
+	itsVXData = jnew JArray<JFloat>(kDefSampleCount);
+	itsVYData = jnew JArray<JFloat>(kDefSampleCount);
 
 	itsIsListeningFlag = false;
 }
diff --git a/libj2dplot/code/JX2DCurveNameList.cpp b/libj2dplot/code/JX2DCurveNameList.cpp
index c0a2c4cb5..d69fec5ca 100644
--- a/libj2dplot/code/JX2DCurveNameList.cpp
+++ b/libj2dplot/code/JX2DCurveNameList.cpp
@@ -54,7 +54,7 @@ JX2DCurveNameList::JX2DCurveNameList
 
 	const JSize count = curveInfo.GetItemCount();
 
-	itsNameList = jnew JPtrArray<JString>(JPtrArrayT::kForgetAll);
+	itsNameList = jnew JPtrArray<JString>(JPtrArrayT::kForgetAll, count);
 
 	AppendRows(count);
 	for (JIndex i=1; i<=count; i++)
diff --git a/libjcore/code/JAliasArray.tmpl b/libjcore/code/JAliasArray.tmpl
index cc893ce55..5f6e4e828 100644
--- a/libjcore/code/JAliasArray.tmpl
+++ b/libjcore/code/JAliasArray.tmpl
@@ -44,7 +44,8 @@ JAliasArray<T>::JAliasArray
 {
 	assert( itsData != nullptr );
 
-	itsIndexArray = jnew JArray<JIndex>(data->GetMinLgSize());
+	itsIndexArray = jnew JArray<JIndex>;
+	itsIndexArray->SetMinLgSize(data->GetMinLgSize());
 	itsIndexArray->SetSortOrder(order);
 
 	SetCompareFunction(compareFn);
diff --git a/libjcore/code/JArray.h b/libjcore/code/JArray.h
index fd18e5f95..d93de691f 100644
--- a/libjcore/code/JArray.h
+++ b/libjcore/code/JArray.h
@@ -18,7 +18,7 @@ class JArray : public JList<T>
 {
 public:
 
-	JArray(const JSize minLgSize = 0);
+	JArray(const JSize minSize = 0);
 	JArray(const JArray<T>& source);
 	JArray(JArray<T>&& dyingSource) noexcept;
 
diff --git a/libjcore/code/JArray.tmpl b/libjcore/code/JArray.tmpl
index ad2d335de..a0f0dedd0 100644
--- a/libjcore/code/JArray.tmpl
+++ b/libjcore/code/JArray.tmpl
@@ -25,6 +25,7 @@
 #include "JArray.h"
 #include "JMinMax.h"
 #include "jMath.h"
+#include <bit>
 #include <string.h>		// for memcpy,memmove
 #include <stdlib.h>		// for qsort
 // we are included by jAssert.h
@@ -38,7 +39,7 @@ inline JSize jArrayLgToSize(const JSize lgSize)
 
 inline JSize jArraySizeToLg(const JSize count)
 {
-	return JLCeil(std::log2(count+1));
+	return std::bit_width(count);
 }
 
 /******************************************************************************
@@ -49,15 +50,13 @@ inline JSize jArraySizeToLg(const JSize count)
 template <class T>
 JArray<T>::JArray
 	(
-	const JSize minLgSize
+	const JSize minSize
 	)
 	:
 	JList<T>(),
-	itsLgSize(JMax(kJArrayDefaultMinLgSize, minLgSize)),
+	itsLgSize(JMax(kJArrayDefaultMinLgSize, jArraySizeToLg(minSize))),
 	itsMinLgSize(itsLgSize)
 {
-	assert( itsMinLgSize < 12 );
-
 	itsItems = jnew T [ jArrayLgToSize(itsLgSize) ];
 }
 
@@ -275,7 +274,7 @@ JArray<T>::CreateItem
 {
 	assert( index > 0 );
 
-	const JSize newLgSize = JMax(itsMinLgSize, jArraySizeToLg(this->GetItemCount()));
+	const JSize newLgSize = JMax(itsMinLgSize, jArraySizeToLg(this->GetItemCount() + 1));
 	if (newLgSize > itsLgSize)
 	{
 		ResizeMemoryAllocation(newLgSize);
diff --git a/libjcore/code/JAsynchDataReceiver.h b/libjcore/code/JAsynchDataReceiver.h
index e53989ccf..b42cd19ca 100644
--- a/libjcore/code/JAsynchDataReceiver.h
+++ b/libjcore/code/JAsynchDataReceiver.h
@@ -21,7 +21,7 @@ class JAsynchDataReceiverT
 
 	enum
 	{
-		kDefaultLgBufferSize = 16
+		kDefaultBufferSize = 65536
 	};
 
 public:
diff --git a/libjcore/code/JAsynchDataReceiver.tmpl b/libjcore/code/JAsynchDataReceiver.tmpl
index 0b511cf59..563852d41 100644
--- a/libjcore/code/JAsynchDataReceiver.tmpl
+++ b/libjcore/code/JAsynchDataReceiver.tmpl
@@ -25,7 +25,7 @@ template <ACE_PEER_STREAM_1>
 JAsynchDataReceiver<ACE_PEER_STREAM_2>::JAsynchDataReceiver()
 	:
 	ACE_Svc_Handler<ACE_PEER_STREAM_2,ACE_SYNCH>(),
-	itsByteBuffer(JAsynchDataReceiverT::kDefaultLgBufferSize)
+	itsByteBuffer(JAsynchDataReceiverT::kDefaultBufferSize)
 {
 	JAsynchDataReceiverX();
 }
@@ -37,7 +37,7 @@ JAsynchDataReceiver<ACE_PEER_STREAM_2>::JAsynchDataReceiver
 	)
 	:
 	ACE_Svc_Handler<ACE_PEER_STREAM_2,ACE_SYNCH>(),
-	itsByteBuffer(JAsynchDataReceiverT::kDefaultLgBufferSize)
+	itsByteBuffer(JAsynchDataReceiverT::kDefaultBufferSize)
 {
 	JAsynchDataReceiverX();
 
@@ -51,7 +51,7 @@ template <ACE_PEER_STREAM_1>
 void
 JAsynchDataReceiver<ACE_PEER_STREAM_2>::JAsynchDataReceiverX()
 {
-	itsRecvBufferSize = 1UL << JAsynchDataReceiverT::kDefaultLgBufferSize;
+	itsRecvBufferSize = JAsynchDataReceiverT::kDefaultBufferSize;
 	itsRecvBuffer     = jnew JUtf8Byte [ itsRecvBufferSize ];
 	itsCancelTaskFlag = nullptr;
 }
diff --git a/libjcore/code/JCoreLibVersion.h b/libjcore/code/JCoreLibVersion.h
index ce6aa633d..2de99095f 100644
--- a/libjcore/code/JCoreLibVersion.h
+++ b/libjcore/code/JCoreLibVersion.h
@@ -44,15 +44,8 @@ static const char* kCurrentJCoreLibVersionStr = "4.2.0";
 //		Fixed bug so original selection is fully cleared after undo/redo.
 //	JArray:
 //		Switched to an exponential reallocation model.
-//		*** Ctor now takes log2(minimum allocation size).
 //	JStyledText:
-//		*** SetBlockSizes() now takes lgSize for both arguments.
-//	JRunArray:
-//		*** Ctor now takes log2(minimum allocation size).
-//	JPtrArray:
-//		*** Ctor now takes log2(minimum allocation size).
-//	JUtf8ByteBuffer:
-//		*** Ctor now takes log2(minimum allocation size).
+//		Renamed SetBlockSizes() to SetLgMinSizes().
 
 // version 4.1.0:
 //
diff --git a/libjcore/code/JMMArrayTable.cpp b/libjcore/code/JMMArrayTable.cpp
index ef5c117ce..fd3b0111c 100644
--- a/libjcore/code/JMMArrayTable.cpp
+++ b/libjcore/code/JMMArrayTable.cpp
@@ -16,6 +16,8 @@
 #include "JMMRecord.h"
 #include "jAssert.h"
 
+	const JSize blockSize = 5000;
+
 /******************************************************************************
  Constructor
 
@@ -34,11 +36,11 @@ JMMArrayTable::JMMArrayTable
 	itsDeletedCount(0),
 	itsSnapshotID(0)
 {
-	itsAllocatedTable = jnew JArray<JMMRecord>(12);
+	itsAllocatedTable = jnew JArray<JMMRecord>(blockSize);
 
 	if (recordDelete)
 	{
-		itsDeletedTable = jnew JArray<JMMRecord>(12);
+		itsDeletedTable = jnew JArray<JMMRecord>(blockSize);
 	}
 }
 
diff --git a/libjcore/code/JMessageProtocol.tmpl b/libjcore/code/JMessageProtocol.tmpl
index defd9f852..6eb068005 100644
--- a/libjcore/code/JMessageProtocol.tmpl
+++ b/libjcore/code/JMessageProtocol.tmpl
@@ -41,6 +41,7 @@ JMessageProtocol<ACE_PEER_STREAM_2>::JMessageProtocol
 	)
 	:
 	JNetworkProtocolBase<ACE_PEER_STREAM_2>(synchSend),
+	itsByteBuffer(JMessageProtocolT::kDefaultBufferSize),
 	itsMessageList(JPtrArrayT::kDeleteAll),
 	itsSeparatorStr(JString::kDoNotNormalize),
 	itsDisconnectStr(JString::kDoNotNormalize)
@@ -56,6 +57,7 @@ JMessageProtocol<ACE_PEER_STREAM_2>::JMessageProtocol
 	)
 	:
 	JNetworkProtocolBase<ACE_PEER_STREAM_2>(synchSend),
+	itsByteBuffer(JMessageProtocolT::kDefaultBufferSize),
 	itsMessageList(JPtrArrayT::kDeleteAll),
 	itsSeparatorStr(JString::kDoNotNormalize),
 	itsDisconnectStr(JString::kDoNotNormalize)
diff --git a/libjcore/code/JPtrArray.h b/libjcore/code/JPtrArray.h
index b7a8a489f..139c76e43 100644
--- a/libjcore/code/JPtrArray.h
+++ b/libjcore/code/JPtrArray.h
@@ -22,7 +22,7 @@ class JPtrArray : public JArray<T*>
 {
 public:
 
-	JPtrArray(const JPtrArrayT::CleanUpAction action, const JSize minLgSize = 0);
+	JPtrArray(const JPtrArrayT::CleanUpAction action, const JSize minSize = 0);
 	JPtrArray(const JPtrArray<T>& source, const JPtrArrayT::CleanUpAction action);
 	JPtrArray(JPtrArray<T>&& dyingSource) noexcept;
 
@@ -95,7 +95,7 @@ class JDCCPtrArray : public JPtrArray<T>
 {
 public:
 
-	JDCCPtrArray(const JPtrArrayT::CleanUpAction action, const JSize minLgSize = 0);
+	JDCCPtrArray(const JPtrArrayT::CleanUpAction action, const JSize minSize = 0);
 	JDCCPtrArray(const JPtrArray<T>& source, const JPtrArrayT::CleanUpAction action);
 };
 
diff --git a/libjcore/code/JPtrArray.tmpl b/libjcore/code/JPtrArray.tmpl
index 5e689ee9c..3b352ee4e 100644
--- a/libjcore/code/JPtrArray.tmpl
+++ b/libjcore/code/JPtrArray.tmpl
@@ -37,10 +37,10 @@ template <class T>
 JPtrArray<T>::JPtrArray
 	(
 	const JPtrArrayT::CleanUpAction	action,
-	const JSize						minLgSize
+	const JSize						minSize
 	)
 	:
-	JArray<T*>(minLgSize),
+	JArray<T*>(minSize),
 	itsCleanUpAction(action)
 {
 }
@@ -91,10 +91,10 @@ template <class T>
 JDCCPtrArray<T>::JDCCPtrArray
 	(
 	const JPtrArrayT::CleanUpAction	action,
-	const JSize						minLgSize
+	const JSize						minSize
 	)
 	:
-	JPtrArray<T>(action, minLgSize)
+	JPtrArray<T>(action, minSize)
 {
 }
 
diff --git a/libjcore/code/JRunArray.h b/libjcore/code/JRunArray.h
index 14457cac9..62b235a7a 100644
--- a/libjcore/code/JRunArray.h
+++ b/libjcore/code/JRunArray.h
@@ -45,7 +45,7 @@ class JRunArray : public JList<T>
 
 public:
 
-	JRunArray(const JSize minLgSize = 0);
+	JRunArray(const JSize minSize = 0);
 	JRunArray(const JRunArray<T>& source);
 	JRunArray(const JRunArray<T>& source, const JIndexRange& range);
 
diff --git a/libjcore/code/JRunArray.tmpl b/libjcore/code/JRunArray.tmpl
index 34d5a5e1c..be7335d99 100644
--- a/libjcore/code/JRunArray.tmpl
+++ b/libjcore/code/JRunArray.tmpl
@@ -36,12 +36,12 @@
 template <class T>
 JRunArray<T>::JRunArray
 	(
-	const JSize minLgSize
+	const JSize minSize
 	)
 	:
 	JList<T>()
 {
-	itsRuns = jnew JArray< JRunArrayItem<T> >(minLgSize);
+	itsRuns = jnew JArray< JRunArrayItem<T> >(minSize);
 }
 
 /******************************************************************************
@@ -67,7 +67,8 @@ JRunArray<T>::JRunArray
 	const JIndexRange&	range
 	)
 {
-	itsRuns = jnew JArray< JRunArrayItem<T> >(source.itsRuns->GetMinLgSize());
+	itsRuns = jnew JArray< JRunArrayItem<T> >;
+	itsRuns->SetMinLgSize(source.itsRuns->GetMinLgSize());
 
 	JIndex runIndex = 1, firstIndexInRun = 1;
 	IteratorInsertSlice(1, source, range, &runIndex, &firstIndexInRun);
diff --git a/libjcore/code/JSTStyler.cpp b/libjcore/code/JSTStyler.cpp
index 7d9f759f1..44624b7a2 100644
--- a/libjcore/code/JSTStyler.cpp
+++ b/libjcore/code/JSTStyler.cpp
@@ -62,7 +62,7 @@ using TextCount = JStyledText::TextCount;
 using TextRange = JStyledText::TextRange;
 
 const JSize kDecimationFactor = 50;
-const JSize kMinLgListSize    = 7;
+const JSize kMinListSize      = 50;
 
 #define DEBUG_TIMING_INFO	0	// boolean
 
@@ -416,7 +416,7 @@ JSTStyler::SetStyle
 JArray<JSTStyler::TokenData>*
 JSTStyler::NewTokenStartList()
 {
-	auto* list = jnew JArray<TokenData>(kMinLgListSize);
+	auto* list = jnew JArray<TokenData>(kMinListSize);
 	list->SetSortOrder(JListT::kSortAscending);
 	list->SetCompareFunction(CompareTokenStarts);
 	return list;
diff --git a/libjcore/code/JStyledText.cpp b/libjcore/code/JStyledText.cpp
index 04924f115..5e8470587 100644
--- a/libjcore/code/JStyledText.cpp
+++ b/libjcore/code/JStyledText.cpp
@@ -188,7 +188,8 @@ JStyledText::SetText
 {
 	ClearUndo();
 
-	JRunArray<JFont> tmpStyle(itsStyles->GetMinLgSize());
+	JRunArray<JFont> tmpStyle;
+	tmpStyle.SetMinLgSize(itsStyles->GetMinLgSize());
 	if (style != nullptr)
 	{
 		tmpStyle = *style;
@@ -455,7 +456,8 @@ JStyledText::ReadPrivateFormat
 	Broadcast(WillBeBusy());
 
 	JString text;
-	JRunArray<JFont> style(itsStyles->GetMinLgSize());
+	JRunArray<JFont> style;
+	style.SetMinLgSize(itsStyles->GetMinLgSize());
 	if (ReadPrivateFormat(input, &text, &style))
 	{
 		SetText(text, &style);
@@ -961,7 +963,8 @@ JStyledText::ReplaceAllInRange
 	)
 {
 	JString text;
-	JRunArray<JFont> styles(itsStyles->GetMinLgSize());
+	JRunArray<JFont> styles;
+	styles.SetMinLgSize(itsStyles->GetMinLgSize());
 	FontIterator styleIter(&styles);
 
 	if (range.charRange.GetCount() == itsText.GetCharacterCount())	// avoid counting characters
@@ -980,7 +983,8 @@ JStyledText::ReplaceAllInRange
 
 	bool changed = false;
 
-	JRunArray<JFont> newStyles(itsStyles->GetMinLgSize());
+	JRunArray<JFont> newStyles;
+	newStyles.SetMinLgSize(itsStyles->GetMinLgSize());
 
 	JStringIterator textIter(&text);
 	while (textIter.Next(regex))
@@ -1742,7 +1746,8 @@ JStyledText::InsertText
 	const JFont&		font
 	)
 {
-	JRunArray<JFont> style(itsStyles->GetMinLgSize());
+	JRunArray<JFont> style;
+	style.SetMinLgSize(itsStyles->GetMinLgSize());
 	style.AppendItems(font, text.GetCharacterCount());
 
 	return InsertText(index, text, style);
@@ -1873,8 +1878,7 @@ JStyledText::CleanText
 		JString tmpText;
 		tmpText.SetMinLgSize(JLCeil(std::log2((**cleanText).GetByteCount()+256)));
 
-		JRunArray<JFont> tmpStyle;
-		tmpStyle.SetMinSize((**cleanStyle).GetRunCount()+16);
+		JRunArray<JFont> tmpStyle((**cleanStyle).GetRunCount()+16);
 
 		JStringIterator iter(*cleanText);
 		JUtf8Character c;
@@ -2656,7 +2660,8 @@ JStyledText::Indent
 		}
 	}
 
-	JRunArray<JFont> style(itsStyles->GetMinLgSize());
+	JRunArray<JFont> style;
+	style.SetMinLgSize(itsStyles->GetMinLgSize());
 
 	JStringIterator textIter(&itsText);
 	textIter.UnsafeMoveTo(JStringIterator::kStartBeforeChar, range.charRange.first, range.byteRange.first);
@@ -3011,7 +3016,8 @@ JStyledText::CleanRightMargin
 	bool changed = false;
 	TextRange origTextRange;
 	JString newText;
-	JRunArray<JFont> newStyles(itsStyles->GetMinLgSize());
+	JRunArray<JFont> newStyles;
+	newStyles.SetMinLgSize(itsStyles->GetMinLgSize());
 
 	TextIndex newCaretIndex;
 	if (selectionRange.IsEmpty())
@@ -3027,7 +3033,8 @@ JStyledText::CleanRightMargin
 
 		TextRange range;
 		JString text;
-		JRunArray<JFont> styles(itsStyles->GetMinLgSize());
+		JRunArray<JFont> styles;
+		styles.SetMinLgSize(itsStyles->GetMinLgSize());
 		*caretIndex = selectionRange.GetFirst();
 		TextIndex tmpCaretIndex;
 		bool first = true;
@@ -3162,7 +3169,8 @@ JStyledText::PrivateCleanRightMargin
 	bool requireSpace      = false;
 
 	JString wordBuffer, spaceBuffer;
-	JRunArray<JFont> wordStyles(itsStyles->GetMinLgSize());
+	JRunArray<JFont> wordStyles;
+	wordStyles.SetMinLgSize(itsStyles->GetMinLgSize());
 	while (index.charIndex <= origTextRange->charRange.last)
 	{
 		JSize spaceCount;
diff --git a/libjcore/code/JStyledText.h b/libjcore/code/JStyledText.h
index b28963d63..e7582c67f 100644
--- a/libjcore/code/JStyledText.h
+++ b/libjcore/code/JStyledText.h
@@ -415,7 +415,7 @@ class JStyledText : virtual public JBroadcaster
 	TextRange	SelectAll() const;
 	TextRange	CharToTextRange(const TextIndex* lineStart, const JCharacterRange& charRange) const;
 
-	void		SetLgBlockSizes(const JSize textLgSize, const JSize styleLgSize);
+	void		SetLgMinSizes(const JSize textLgSize, const JSize styleLgSize);
 
 	static std::weak_ordering
 		CompareCharacterIndices(const TextIndex& i, const TextIndex& j);
@@ -941,12 +941,12 @@ JStyledText::GetBeyondEnd()
 }
 
 /******************************************************************************
- SetLgBlockSizes
+ SetLgMinSizes
 
  ******************************************************************************/
 
 inline void
-JStyledText::SetLgBlockSizes
+JStyledText::SetLgMinSizes
 	(
 	const JSize textLgSize,
 	const JSize styleLgSize
diff --git a/libjcore/code/JTextEditor.cpp b/libjcore/code/JTextEditor.cpp
index 2e4f24f7a..c643881b3 100644
--- a/libjcore/code/JTextEditor.cpp
+++ b/libjcore/code/JTextEditor.cpp
@@ -233,7 +233,7 @@ JTextEditor::JTextEditor
 
 	if (type == kFullEditor)
 	{
-		itsText->SetLgBlockSizes(12, 7);	// 12 = 4KB, 7 = 128
+		itsText->SetLgMinSizes(12, 7);	// 12 = 4KB, 7 = 128
 		itsLineStarts->SetMinLgSize(7);
 		itsLineGeom->SetMinLgSize(7);
 	}
@@ -1544,7 +1544,7 @@ JTextEditor::GetCmdStatus
 	)
 	const
 {
-	JArray<bool> flags(6);
+	JArray<bool> flags(kCmdCount);
 	for (JIndex i=1; i<=kCmdCount; i++)
 	{
 		flags.AppendItem(false);
diff --git a/libjcore/code/JTreeList.cpp b/libjcore/code/JTreeList.cpp
index 719bc2197..6e13c720b 100644
--- a/libjcore/code/JTreeList.cpp
+++ b/libjcore/code/JTreeList.cpp
@@ -169,7 +169,7 @@ JTreeList::Close
 		JIndex index;
 		if (FindNode(node, &index))
 		{
-			JPtrArray<JTreeNode> nodeList(JPtrArrayT::kDeleteAll, 7);
+			JPtrArray<JTreeNode> nodeList(JPtrArrayT::kDeleteAll, 100);
 			const_cast<JTreeNode*>(node)->CollectDescendants(&nodeList);
 
 			JIndex j;
@@ -352,7 +352,7 @@ JTreeList::CloseDescendants
 {
 	Close(node);
 
-	JPtrArray<JTreeNode> nodeList(JPtrArrayT::kDeleteAll, 7);
+	JPtrArray<JTreeNode> nodeList(JPtrArrayT::kDeleteAll, 100);
 	const_cast<JTreeNode*>(node)->CollectDescendants(&nodeList);
 
 	for (const auto* n : nodeList)
diff --git a/libjcore/code/JUndoRedoChain.cpp b/libjcore/code/JUndoRedoChain.cpp
index 0c8bb36b4..be244f92c 100644
--- a/libjcore/code/JUndoRedoChain.cpp
+++ b/libjcore/code/JUndoRedoChain.cpp
@@ -32,8 +32,7 @@ JUndoRedoChain::JUndoRedoChain
 {
 	if (useMultipleUndo)
 	{
-		itsUndoList = jnew JPtrArray<JUndo>(JPtrArrayT::kDeleteAll);
-		itsUndoList->SetMinSize(itsMaxUndoCount);
+		itsUndoList = jnew JPtrArray<JUndo>(JPtrArrayT::kDeleteAll, itsMaxUndoCount);
 	}
 }
 
diff --git a/libjcore/code/JUtf8ByteBuffer.cpp b/libjcore/code/JUtf8ByteBuffer.cpp
index c8e2e4db0..2fd02c76a 100644
--- a/libjcore/code/JUtf8ByteBuffer.cpp
+++ b/libjcore/code/JUtf8ByteBuffer.cpp
@@ -18,10 +18,10 @@
 
 JUtf8ByteBuffer::JUtf8ByteBuffer
 	(
-	const JSize minLgSize
+	const JSize minSize
 	)
 	:
-	JArray<JUtf8Byte>(minLgSize)
+	JArray<JUtf8Byte>(minSize)
 {
 }
 
diff --git a/libjcore/code/JUtf8ByteBuffer.h b/libjcore/code/JUtf8ByteBuffer.h
index e74978220..0886e8e07 100644
--- a/libjcore/code/JUtf8ByteBuffer.h
+++ b/libjcore/code/JUtf8ByteBuffer.h
@@ -15,7 +15,7 @@ class JUtf8ByteBuffer : public JArray<JUtf8Byte>
 {
 public:
 
-	JUtf8ByteBuffer(const JSize minLgSize = 10);
+	JUtf8ByteBuffer(const JSize minSize = 1024);
 
 	~JUtf8ByteBuffer() override;
 
diff --git a/libjcore/code/JUtf8Character.h b/libjcore/code/JUtf8Character.h
index dd471e23e..5bd9f1be3 100644
--- a/libjcore/code/JUtf8Character.h
+++ b/libjcore/code/JUtf8Character.h
@@ -175,9 +175,6 @@ JUtf8Character::SetIgnoreBadUtf8
 /******************************************************************************
  Assignment operator
 
-	We do not copy block size because we assume the client has set them
-	appropriately.
-
  ******************************************************************************/
 
 inline JUtf8Character&
diff --git a/libjcore/code/jStreamUtil.cpp b/libjcore/code/jStreamUtil.cpp
index 16b998280..5a4ab3f2c 100644
--- a/libjcore/code/jStreamUtil.cpp
+++ b/libjcore/code/jStreamUtil.cpp
@@ -789,7 +789,7 @@ JReadAll
 	const JSize bufLength = 1024;
 
 	char readBuf[ bufLength ];
-	JUtf8ByteBuffer byteBuf(10);
+	JUtf8ByteBuffer byteBuf(bufLength);
 	while (true)
 	{
 		size_t byteCount;
diff --git a/libjexpr/code/JExprEditor.cpp b/libjexpr/code/JExprEditor.cpp
index 260d9a439..50c2389f3 100644
--- a/libjexpr/code/JExprEditor.cpp
+++ b/libjexpr/code/JExprEditor.cpp
@@ -1429,7 +1429,7 @@ JExprEditor::GetCmdStatus
 	)
 	const
 {
-	JArray<bool> flags(5);
+	JArray<bool> flags(kCmdCount);
 	for (JIndex i=1; i<=kCmdCount; i++)
 	{
 		flags.AppendItem(false);
diff --git a/libjexpr/code/JNaryFunction.cpp b/libjexpr/code/JNaryFunction.cpp
index 7ed6709db..0eaca72f2 100644
--- a/libjexpr/code/JNaryFunction.cpp
+++ b/libjexpr/code/JNaryFunction.cpp
@@ -14,7 +14,7 @@
 #include "JNaryFunction.h"
 #include <jx-af/jcore/jAssert.h>
 
-const JSize kLgMaxReasonableArgCount = 3;
+const JSize kMaxReasonableArgCount = 10;
 
 /******************************************************************************
  Constructor
@@ -32,7 +32,7 @@ JNaryFunction::JNaryFunction
 {
 	if (argList == nullptr)
 	{
-		itsArgList = jnew JPtrArray<JFunction>(JPtrArrayT::kDeleteAll, kLgMaxReasonableArgCount);
+		itsArgList = jnew JPtrArray<JFunction>(JPtrArrayT::kDeleteAll, kMaxReasonableArgCount);
 	}
 	else
 	{
@@ -65,7 +65,7 @@ JNaryFunction::JNaryFunction
 	:
 	JFunctionWithArgs(source)
 {
-	itsArgList = jnew JPtrArray<JFunction>(JPtrArrayT::kDeleteAll, kLgMaxReasonableArgCount);
+	itsArgList = jnew JPtrArray<JFunction>(JPtrArrayT::kDeleteAll, kMaxReasonableArgCount);
 
 	const JSize argCount = source.itsArgList->GetItemCount();
 
diff --git a/libjx/code/JXBusyIconTask.cpp b/libjx/code/JXBusyIconTask.cpp
index 1d1264d18..18716eb44 100644
--- a/libjx/code/JXBusyIconTask.cpp
+++ b/libjx/code/JXBusyIconTask.cpp
@@ -29,6 +29,8 @@ static JXPM kBusyIcon[] =
 	jx_busy_5_small, jx_busy_6_small, jx_busy_7_small, jx_busy_8_small
 };
 
+const JSize kBusyIconCount = sizeof(kBusyIcon)/sizeof(JXPM);
+
 const JSize kAnimationPeriod = 100;		// milliseconds
 
 /******************************************************************************
@@ -43,7 +45,7 @@ JXBusyIconTask::JXBusyIconTask
 	:
 	JXAnimationTask(widget)
 {
-	itsImageList = jnew JPtrArray<JXImage>(JPtrArrayT::kForgetAll);
+	itsImageList = jnew JPtrArray<JXImage>(JPtrArrayT::kForgetAll, kBusyIconCount);
 
 	JXImageCache* cache = widget->GetDisplay()->GetImageCache();
 	for (const auto& xpm : kBusyIcon)
diff --git a/libjx/code/JXCursorAnimator.cpp b/libjx/code/JXCursorAnimator.cpp
index bd60e0938..19b2b410b 100644
--- a/libjx/code/JXCursorAnimator.cpp
+++ b/libjx/code/JXCursorAnimator.cpp
@@ -132,7 +132,7 @@ JXCursorAnimator::InitFrames
 	JXDisplay* display
 	)
 {
-	itsFrames = jnew JArray<JCursorIndex>;
+	itsFrames = jnew JArray<JCursorIndex>(kBeachBallFrameCount);
 
 	for (JUnsignedOffset i=0; i<kBeachBallFrameCount; i++)
 	{
diff --git a/libjx/code/JXDocumentManager.cpp b/libjx/code/JXDocumentManager.cpp
index 6f22c5751..7dcc929b6 100644
--- a/libjx/code/JXDocumentManager.cpp
+++ b/libjx/code/JXDocumentManager.cpp
@@ -656,8 +656,7 @@ JXDocumentManager::UpdateDocumentMenu
 	// include partial paths for files with same names
 
 	const JSize count = itsDocList->GetItemCount();
-	JPtrArray<JString> nameList(JPtrArrayT::kDeleteAll);
-	nameList.SetMinSize(count);
+	JPtrArray<JString> nameList(JPtrArrayT::kDeleteAll, count);
 
 	for (const auto& info : *itsDocList)
 	{
diff --git a/libjx/code/JXFileListTable.cpp b/libjx/code/JXFileListTable.cpp
index 4c7990904..f9d0231c4 100644
--- a/libjx/code/JXFileListTable.cpp
+++ b/libjx/code/JXFileListTable.cpp
@@ -81,12 +81,12 @@ JXFileListTable::JXFileListTable
 	itsEditMenuProvider   = nullptr;
 	itsEditMenu           = nullptr;
 
-	itsFileList = jnew JPtrArray<JString>(JPtrArrayT::kDeleteAll, 8);
+	itsFileList = jnew JPtrArray<JString>(JPtrArrayT::kDeleteAll, 100);
 	// UNIX file system is case-sensitive.
 	itsFileList->SetCompareFunction(JCompareStringsCaseSensitive);
 	ListenTo(itsFileList);
 
-	itsVisibleList = jnew JArray<VisInfo>(8);
+	itsVisibleList = jnew JArray<VisInfo>(100);
 	itsVisibleList->SetSortOrder(JListT::kSortAscending);
 
 	itsFileIcon = GetDisplay()->GetImageCache()->GetImage(jx_plain_file_small);
diff --git a/libjx/code/JXSpellCheckerDialog.cpp b/libjx/code/JXSpellCheckerDialog.cpp
index 6b020000d..242c9ec57 100644
--- a/libjx/code/JXSpellCheckerDialog.cpp
+++ b/libjx/code/JXSpellCheckerDialog.cpp
@@ -41,7 +41,7 @@ JXSpellCheckerDialog::JXSpellCheckerDialog
 	itsCurrentIndex(range.GetFirst()),
 	itsFoundErrorsFlag(false)
 {
-	itsSuggestionList = jnew JPtrArray<JString>(JPtrArrayT::kDeleteAll, 5);
+	itsSuggestionList = jnew JPtrArray<JString>(JPtrArrayT::kDeleteAll, 25);
 	BuildWindow();
 }
 
diff --git a/libjx/testui/code/AnimateHelpMenuTask.cpp b/libjx/testui/code/AnimateHelpMenuTask.cpp
index 3aaf29a94..79af66469 100644
--- a/libjx/testui/code/AnimateHelpMenuTask.cpp
+++ b/libjx/testui/code/AnimateHelpMenuTask.cpp
@@ -33,7 +33,7 @@ AnimateHelpMenuTask::AnimateHelpMenuTask
 {
 	itsMenu = menu;
 
-	itsImageList = jnew JPtrArray<JXImage>(JPtrArrayT::kDeleteAll);
+	itsImageList = jnew JPtrArray<JXImage>(JPtrArrayT::kDeleteAll, kHelpIconCount);
 
 	JXDisplay* display = itsMenu->GetDisplay();
 	for (JIndex i=1; i<=kHelpIconCount; i++)