Свойство text-stroke-width

text-stroke-width: размер;

<!DOCTYPE html>
<html lang='ru'>
<head>
<meta charset='UTF-8'>
<meta name='viewport' content='width=device-width, initial-scale=1.0'>
<title>Document</title>
</head>
<body>
<style>
 #test {
 background-color: black;
 padding: 15px;
 color: white;
 }
 #hh {
 font: bold Arial;
 -webkit-text-stroke: red; 
 -webkit-text-stroke-width: 5px;
 color: transparent;
 }
 </style>
 <div id='test'>
 <h2 id='hh'>W E B I K</h2>
 </div>
</body>
</html>