diff --git a/block.go b/block.go
index 9fc5f5f..85e928d 100644
--- a/block.go
+++ b/block.go
@@ -85,7 +85,7 @@ func (b Block) drawBorder(buf Buffer) {
 
 func (b Block) drawBorderLabel(buf Buffer) {
 	maxTxtW := b.area.Dx() - 2
-	tx := DTrimTxCls(TextCells(b.BorderLabel, b.BorderLabelFg, b.BorderLabelBg), maxTxtW)
+	tx := DTrimTxCls(DefaultTxBuilder.Build(b.BorderLabel, b.BorderLabelFg, b.BorderLabelBg), maxTxtW)
 
 	for i, w := 0, 0; i < len(tx); i++ {
 		buf.Set(b.area.Min.X+1+w, b.area.Min.Y, tx[i])
diff --git a/block_main.go b/block_main.go
index a55160c..6e147f0 100644
--- a/block_main.go
+++ b/block_main.go
@@ -11,7 +11,7 @@ func main() {
 	b := termui.NewBlock()
 	b.Width = 20
 	b.Height = 30
-	b.BorderLabel = "HELLO WORLD"
+	b.BorderLabel = "[HELLO](fg-red,bg-white) [WORLD](fg-blue,bg-green)"
 
 	termui.Render(b)
 	<-termui.EventCh()
diff --git a/buffer.go b/buffer.go
index ea2064a..3cc562f 100644
--- a/buffer.go
+++ b/buffer.go
@@ -15,7 +15,7 @@ type Cell struct {
 
 // Buffer is a renderable rectangle cell data container.
 type Buffer struct {
-	Area    *image.Rectangle // selected drawing area
+	Area    image.Rectangle // selected drawing area
 	CellMap map[image.Point]Cell
 }
 
@@ -50,7 +50,7 @@ func (b Buffer) Bounds() image.Rectangle {
 }
 
 // SetArea assigns a new rect area to Buffer b.
-func (b Buffer) SetArea(r image.Rectangle) {
+func (b *Buffer) SetArea(r image.Rectangle) {
 	b.Area.Max = r.Max
 	b.Area.Min = r.Min
 }
@@ -71,24 +71,15 @@ func (b Buffer) Merge(bs ...Buffer) {
 		for p, v := range buf.CellMap {
 			b.Set(p.X, p.Y, v)
 		}
-		b.SetArea(b.Area.Union(*buf.Area))
+		b.SetArea(b.Area.Union(buf.Area))
 	}
 }
 
-// Point for adapting use, will be removed after resolving bridging.
-type Point struct {
-	X  int
-	Y  int
-	Ch rune
-	Fg Attribute
-	Bg Attribute
-}
-
 // NewBuffer returns a new Buffer
 func NewBuffer() Buffer {
 	return Buffer{
 		CellMap: make(map[image.Point]Cell),
-		Area:    &image.Rectangle{}}
+		Area:    image.Rectangle{}}
 }
 
 // Fill fills the Buffer b with ch,fg and bg.
diff --git a/render.go b/render.go
index d1a5891..c471238 100644
--- a/render.go
+++ b/render.go
@@ -18,12 +18,13 @@ func Init() error {
 	Body.X = 0
 	Body.Y = 0
 	Body.BgColor = theme.BodyBg
-	defer func() {
-		w, _ := tm.Size()
-		Body.Width = w
-		evtListen()
-	}()
-	return tm.Init()
+	if err := tm.Init(); err != nil {
+		return err
+	}
+	w, _ := tm.Size()
+	Body.Width = w
+	evtListen()
+	return nil
 }
 
 // Close finalizes termui library,
@@ -53,7 +54,7 @@ func Render(bs ...Bufferer) {
 		buf := b.Buffer()
 		// set cels in buf
 		for p, c := range buf.CellMap {
-			if true { //}p.In(buf.Area) {
+			if p.In(buf.Area) {
 				tm.SetCell(p.X, p.Y, c.Ch, toTmAttr(c.Fg), toTmAttr(c.Bg))
 			}
 		}
diff --git a/textbuilder.go b/textbuilder.go
index 4c7f2af..79271fd 100644
--- a/textbuilder.go
+++ b/textbuilder.go
@@ -1,7 +1,6 @@
 package termui
 
 import (
-	"fmt"
 	"regexp"
 	"strings"
 )
@@ -11,6 +10,9 @@ type TextBuilder interface {
 	Build(s string, fg, bg Attribute) []Cell
 }
 
+// DefaultTxBuilder is set to be MarkdownTxBuilder.
+var DefaultTxBuilder = NewMarkdownTxBuilder()
+
 // MarkdownTxBuilder implements TextBuilder interface, using markdown syntax.
 type MarkdownTxBuilder struct {
 	baseFg  Attribute
@@ -55,10 +57,12 @@ func (mtb MarkdownTxBuilder) readAttr(s string) (Attribute, Attribute) {
 
 	updateAttr := func(a Attribute, attrs []string) Attribute {
 		for _, s := range attrs {
+			// replace the color
 			if c, ok := colorMap[s]; ok {
-				a &= 0xFF00 //erase clr 0 ~ 8 bits
+				a &= 0xFF00 // erase clr 0 ~ 8 bits
 				a |= c      // set clr
 			}
+			// add attrs
 			if c, ok := attrMap[s]; ok {
 				a |= c
 			}
@@ -91,7 +95,7 @@ func (mtb *MarkdownTxBuilder) reset() {
 	mtb.markers = []marker{}
 }
 
-// parse
+// parse streams and parses text into normalized text and render sequence.
 func (mtb *MarkdownTxBuilder) parse(str string) {
 	rs := str2runes(str)
 	normTx := []rune{}
@@ -108,19 +112,14 @@ func (mtb *MarkdownTxBuilder) parse(str string) {
 		accBrackt = false
 		cntSquare = 0
 	}
-
+	// pipe stacks into normTx and clear
 	rollback := func() {
 		normTx = append(normTx, square...)
 		normTx = append(normTx, brackt...)
 		reset()
 	}
-
+	// chop first and last
 	chop := func(s []rune) []rune {
-		defer func() {
-			if r := recover(); r != nil {
-				fmt.Println(string(s))
-			}
-		}()
 		return s[1 : len(s)-1]
 	}
 
@@ -185,6 +184,7 @@ func (mtb *MarkdownTxBuilder) parse(str string) {
 	mtb.plainTx = normTx
 }
 
+// Build implements TextBuilder interface.
 func (mtb MarkdownTxBuilder) Build(s string, fg, bg Attribute) []Cell {
 	mtb.baseFg = fg
 	mtb.baseBg = bg
@@ -204,6 +204,7 @@ func (mtb MarkdownTxBuilder) Build(s string, fg, bg Attribute) []Cell {
 	return cs
 }
 
+// NewMarkdownTxBuilder returns a TextBuilder employing markdown syntax.
 func NewMarkdownTxBuilder() TextBuilder {
 	return MarkdownTxBuilder{}
 }