diff --git a/changes/3.3.0.md b/changes/3.3.0.md
index e6f434ef05..b809a818f2 100644
--- a/changes/3.3.0.md
+++ b/changes/3.3.0.md
@@ -1,3 +1,4 @@
  * Change shape of Peseta sign to `P` with crossbar (#451).
  * Add Cyrillic Fita (#617).
- * Add a more rounded variant of `D` (#616).
\ No newline at end of file
+ * Add a more rounded variant of `D` (#616).
+ * Add support for open number sign (`VXBI` and `VXBJ`, #621).
\ No newline at end of file
diff --git a/glyphs/symbol-punctuation.ptl b/glyphs/symbol-punctuation.ptl
index a1b677d83b..b4183f308c 100644
--- a/glyphs/symbol-punctuation.ptl
+++ b/glyphs/symbol-punctuation.ptl
@@ -1010,29 +1010,54 @@ glyph-block Symbol-Punctuation-Slashes-And-Number-Sign : begin
 		save 'backslash.right'
 
 	do "numbersign"
-		local nsTop : mix symbolMid parenTop 0.85
-		local nsBot : mix symbolMid parenBot 0.85
-		local fine : adviceBlackness 3.5
-		local l : SB - fine / 2
-		local r : RightSB + fine / 2
-		local hsp : ((r - l) - (fine * 2 * HVContrast)) * 0.3
-
-		sketch # numbersign.upright
-			include : HBar l r [mix nsTop nsBot 0.3]
-			include : HBar l r [mix nsTop nsBot 0.7]
-			include : VBarLeft  (l + hsp) nsBot nsTop fine
-			include : VBarRight (r - hsp) nsBot nsTop fine
-			save 'numbersign.upright'
-
-		sketch # numbersign.slanted
-			local x : hsp + fine / 2 * HVContrast
-			local w : (r - l) * 0.15
-			local shift : w / 3
-			include : HBar (l + shift) (r + shift) [mix nsTop nsBot 0.3]
-			include : HBar (l - shift) (r - shift) [mix nsTop nsBot 0.7]
-			include : SlashShape (l + x - w) (l + x + w) nsTop nsBot fine
-			include : SlashShape (r - x - w) (r - x + w) nsTop nsBot fine
-			save 'numbersign.slanted'
+		define nsTop : mix symbolMid parenTop 0.85
+		define nsBot : mix symbolMid parenBot 0.85
+		define fine : adviceBlackness 3.5
+
+		define pFineOpen (1 / 8)
+		define l : SB - fine / 2
+		define r : RightSB + fine / 2
+		define hsp : ((r - l) - (fine * 2 * HVContrast)) * 0.3
+
+		define [UprightHBars] : union
+			HBar l r [mix nsTop nsBot 0.3]
+			HBar l r [mix nsTop nsBot 0.7]
+		define [UprightVBars p] : union
+			VBarLeft  (l + hsp + p * fine) nsBot nsTop fine
+			VBarRight (r - hsp - p * fine) nsBot nsTop fine
+
+
+		create-glyph 'numbersign.upright' : union
+			UprightHBars
+			UprightVBars 0
+
+		create-glyph 'numbersign.uprightOpen' : union
+			UprightVBars pFineOpen
+			difference
+				UprightHBars
+				Rect nsTop nsBot (l + hsp + fine * (0.5 + pFineOpen)) (r - hsp - fine * (0.5 + pFineOpen))
+
+		define x : hsp + fine / 2 * HVContrast
+		define w : (r - l) * 0.15
+		define shift : w / 3
+		define [SlantedHBars] : union
+			HBar (l + shift) (r + shift) [mix nsTop nsBot 0.3]
+			HBar (l - shift) (r - shift) [mix nsTop nsBot 0.7]
+		define [SlantedVBars p] : union
+			SlashShape (l + x - w + p * fine) (l + x + w + p * fine) nsTop nsBot fine
+			SlashShape (r - x - w - p * fine) (r - x + w - p * fine) nsTop nsBot fine
+
+		create-glyph 'numbersign.slanted' : union [SlantedHBars] [SlantedVBars 0]
+		create-glyph 'numbersign.slantedOpen' : union
+			SlantedVBars pFineOpen
+			difference
+				SlantedHBars
+				spiro-outline
+					corner (l + x + w + pFineOpen * fine) nsTop
+					corner (r - x + w - pFineOpen * fine) nsTop
+					corner (r - x - w - pFineOpen * fine) nsBot
+					corner (l + x - w + pFineOpen * fine) nsBot
+
 
 		select-variant 'numbersign' '#'
 
diff --git a/params/variants.toml b/params/variants.toml
index 2746942822..8b0a40c73f 100644
--- a/params/variants.toml
+++ b/params/variants.toml
@@ -720,6 +720,18 @@ sampler = '#'
 description = 'Number sign with slanted bars'
 variant.numbersign = 'slanted'
 
+[simple.v-numbersign-upright-open]
+tag = 'VXBI'
+sampler = '#'
+description = 'Number sign with vertical bars and open inner'
+variant.numbersign = 'uprightOpen'
+
+[simple.v-numbersign-slanted-open]
+tag = 'VXBJ'
+sampler = '#'
+description = 'Number sign with slanted bars and open inner'
+variant.numbersign = 'slantedOpen'
+
 [simple.v-ampersand-closed]
 tag = 'VXAG'
 sampler = '&'