diff --git a/src/Buffer.php b/src/Buffer.php
index bd3b581..3751ebe 100644
--- a/src/Buffer.php
+++ b/src/Buffer.php
@@ -173,7 +173,7 @@ public function readString($length, $round = 0, $charset = null)
             $charsetFrom = isset($this->charset) ? $this->charset : mb_internal_encoding();
             $charsetTo = isset($charset) ? $charset : mb_internal_encoding();
             if (isset($str) && (strtolower($charsetFrom) != strtolower($charsetTo))) {
-                $str = mb_convert_encoding($str, $charsetTo, $this->charset);
+                $str = mb_convert_encoding($str, $charsetTo, $charsetFrom);
             }
 
             return $str;
@@ -213,7 +213,26 @@ public function read($length = null)
     }
 
     /**
-     * @param $data
+     * @param string $data
+     * @param int $maxLength
+     *
+     * @return int
+     */
+    public function lengthBytes($data, $maxLength = null, $charset = null)
+    {
+        $charsetTo = isset($this->charset) ? $this->charset : mb_internal_encoding();
+        $charsetFrom = isset($charset) ? $charset : mb_internal_encoding();
+        if (isset($data) && (strtolower($charsetTo) != strtolower($charsetFrom))) {
+            $data = mb_convert_encoding($data, $charsetTo, $charsetFrom);
+        }
+        if (isset($data) && isset($maxLength)) {
+            $data = mb_strcut($data, 0, $maxLength, $charsetTo);
+        }
+        return \strlen($data);
+    }
+
+    /**
+     * @param string $data
      * @param int|string $length
      * @param null       $charset
      *
@@ -226,7 +245,9 @@ public function writeString($data, $length = '*', $charset = null)
         if (isset($data) && (strtolower($charsetFrom) != strtolower($charsetTo))) {
             $data = mb_convert_encoding($data, $charsetTo, $charsetFrom);
         }
-        //file_put_contents("/var/encuestas/test.txt", "To: " . $charsetTo . " FROM:" . $charsetFrom . "\n", FILE_APPEND | LOCK_EX);
+        if (isset($length) && ($length != '*')) {
+            $data = mb_strcut($data, 0, $length, $charsetTo);
+        }
         return $this->write(pack('A' . $length, $data));
     }
 
diff --git a/src/Sav/Record/Info/LongStringValueLabels.php b/src/Sav/Record/Info/LongStringValueLabels.php
index e804588..5fcb696 100644
--- a/src/Sav/Record/Info/LongStringValueLabels.php
+++ b/src/Sav/Record/Info/LongStringValueLabels.php
@@ -45,15 +45,17 @@ public function write(Buffer $buffer)
                 throw new \InvalidArgumentException('values required');
             }
             $width = (int) $data['width'];
-            $localBuffer->writeInt(mb_strlen($varName));
-            $localBuffer->writeString($varName, mb_strlen($varName));
+            $varLengthBytes = $buffer->lengthBytes($varName);
+            $localBuffer->writeInt($varLengthBytes);
+            $localBuffer->writeString($varName, $varLengthBytes);
             $localBuffer->writeInt($width);
             $localBuffer->writeInt(Utils::is_countable($data['values']) ? \count($data['values']) : 0);
             foreach ($data['values'] as $value => $label) {
                 $localBuffer->writeInt($width);
                 $localBuffer->writeString($value, $width);
-                $localBuffer->writeInt(mb_strlen($label));
-                $localBuffer->writeString($label, mb_strlen($label));
+                $labelLengthBytes = $buffer->lengthBytes($label);
+                $localBuffer->writeInt($labelLengthBytes);
+                $localBuffer->writeString($label, $labelLengthBytes);
             }
         }
 
diff --git a/src/Sav/Record/Info/VariableAttributes.php b/src/Sav/Record/Info/VariableAttributes.php
index 46a90b2..5a1e088 100644
--- a/src/Sav/Record/Info/VariableAttributes.php
+++ b/src/Sav/Record/Info/VariableAttributes.php
@@ -44,7 +44,7 @@ public function write(Buffer $buffer)
 
         if ($lines !== []) {
             $data            = implode('/', $lines);
-            $this->dataCount = mb_strlen($data);
+            $this->dataCount = \strlen($data);
             parent::write($buffer);
             $buffer->writeString($data);
         }
diff --git a/src/Sav/Record/ValueLabel.php b/src/Sav/Record/ValueLabel.php
index 8ef3ae0..900c539 100644
--- a/src/Sav/Record/ValueLabel.php
+++ b/src/Sav/Record/ValueLabel.php
@@ -97,22 +97,16 @@ public function write(Buffer $buffer)
         $buffer->writeInt(self::TYPE);
         $buffer->writeInt(\count($this->labels));
         foreach ($this->labels as $item) {
-            $labelLength      = min(mb_strlen($item['label']), self::LABEL_MAX_LENGTH);
-            $label            = mb_substr($item['label'], 0, $labelLength);
-            $labelLengthBytes = mb_strlen($label, '8bit');
-            while ($labelLengthBytes > 255) {
-                // Strip one char, can be multiple bytes
-                $label            = mb_substr($label, 0, -1);
-                $labelLengthBytes = mb_strlen($label, '8bit');
-            }
-
+            $labelLengthBytes = $buffer->lengthBytes($item['label'], self::LABEL_MAX_LENGTH);
+            $labelLengthBytesRound = Utils::roundUp($labelLengthBytes + 1, 8) - 1;
+            
             if ($convertToDouble) {
                 $item['value'] = Utils::stringToDouble($item['value']);
             }
 
             $buffer->writeDouble($item['value']);
             $buffer->write(\chr($labelLengthBytes));
-            $buffer->writeString($label, Utils::roundUp($labelLengthBytes + 1, 8) - 1);
+            $buffer->writeString($item['label'], $labelLengthBytesRound);
         }
 
         // Value label variable record.
diff --git a/src/Sav/Record/Variable.php b/src/Sav/Record/Variable.php
index 3ae6eb8..cd8f7ee 100644
--- a/src/Sav/Record/Variable.php
+++ b/src/Sav/Record/Variable.php
@@ -141,17 +141,10 @@ public function write(Buffer $buffer)
         $buffer->writeString($this->name, 8);
 
         if ($hasLabel) {
-            // Maxlength is 255 bytes, since we write utf8 a char can be multiple bytes
-            $labelLength      = min(mb_strlen($this->label), 255);
-            $label            = mb_substr($this->label, 0, $labelLength);
-            $labelLengthBytes = mb_strlen($label, '8bit');
-            while ($labelLengthBytes > 255) {
-                // Strip one char, can be multiple bytes
-                $label            = mb_substr($label, 0, -1);
-                $labelLengthBytes = mb_strlen($label, '8bit');
-            }
+            $labelLengthBytes = $buffer->lengthBytes($this->label, self::REAL_VLS_CHUNK);
+            $labelLengthBytesRound = Utils::roundUp($labelLengthBytes, 4);
             $buffer->writeInt($labelLengthBytes);
-            $buffer->writeString($label, Utils::roundUp($labelLengthBytes, 4));
+            $buffer->writeString($this->label, $labelLengthBytesRound);
         }
 
         // TODO: test
@@ -181,7 +174,6 @@ public function write(Buffer $buffer)
                 $buffer->writeInt($format); // Print format
                 $buffer->writeInt($format); // Write format
                 $buffer->writeString($this->getSegmentName($i - 1), 8);
-
                 $this->writeBlank($buffer, $segmentWidth);
             }
         }
@@ -222,6 +214,6 @@ public function getSegmentName($seg = 0)
             return mb_strtoupper($this->name);
         }
         $sufix = str_pad($str, 2, "_", STR_PAD_LEFT);
-        return mb_strtoupper(mb_substr($this->name.$sufix, 0, 8));
+        return mb_strtoupper(mb_strcut($this->name.$sufix, 0, 8));
     }
 }