Change background size, width, height to match global’s image dimensions
<style>
.div1{
background-image: url("http://global.k-state.edu/images/cncp-certificates/CE-Certificate-Large-notext-horizontal.jpg");
background-size: 1024px 750px;
background-repeat: no-repeat;
border: none;
height: 750px;
box-sizing: border-box;
padding: 100px 20px 0;
font-family: san serif;
text-align:center;
font-weight:bold;
font-size: 2em;}
h1,h2,h3,h4,h5{margin:0 0 0.25em;}
h2 { font: italic bold;}
body,html{padding:0;margin:0;}
</style>

<div class="div1"> 
<br /><br /><br />
<h4>awards this certificate of completion in:</h4><br />
<h2>Title of Course Here</h2>
<h4>to</h4>
<h3>{{student_name}}</h3>
<h5>Certification Hours: 3</h5>
<h5>{{completion_date}}</h5>
</div>

<p style="page-break-after: always;">&nbsp;</p>
<p style="page-break-before: always;">&nbsp;</p>

<style>
.container{
background-image: url("http://global.k-state.edu/images/certificates/GEAPS-cert.jpg");
background-size: 1024px 768px;
background-repeat: no-repeat;
border: none;
width: 1024px;
height: 768px;
box-sizing: border-box;
padding: 100px 20px 0;
font-family: san serif;
text-align:center;
font-weight:bold;
font-size: 2em;}
h1,h2,h3,h4,h5{margin:0 0 0.25em;}
h2 { font: italic bold; font-size: .75em}
body,html{padding:0;margin:0;}
</style>
<div class="container">
<br /><br /><br />
<div style="display:block; margin-top: 220px;"><h2>{{student_name}} on {{completion_date}} in GEAPS 524: Grain Drying</h2>
</div>
</div>

Success w/ 2 images but GEAPS image overflows to 2 pages
<style>
.div1{
background-image: url("http://global.k-state.edu/images/cncp-certificates/CE-Certificate-Large-notext-horizontal.jpg");
background-size: 1024px 768px;
background-repeat: no-repeat;
border: none;
height: 768px;
box-sizing: border-box;
padding: 100px 20px 0;
font-family: san serif;
text-align:center;
font-weight:bold;
font-size: 2em;}
h1,h2,h3,h4,h5{margin:0 0 0.25em;}
h2 { font: italic bold;}
body,html{padding:0;margin:0;}
</style>

<div class="div1"> 
<br /><br /><br />
<h4>awards this certificate of completion in:</h4><br />
<h2>Title of Course Here</h2>
<h4>to</h4>
<h3>{{student_name}}</h3>
<h5>Certification Hours: 3</h5>
<h5>{{completion_date}}</h5>
</div>

<p style="page-break-after: always;">&nbsp;</p>
<p style="page-break-before: always;">&nbsp;</p>

<style>
.container{
background-image: url("http://global.k-state.edu/images/certificates/GEAPS-cert.jpg");
background-size: 1030px 800px;
background-repeat: no-repeat;
border: none;
width: 1030px;
height: 795px;
box-sizing: border-box;
padding: 100px 20px 0;
font-family: san serif;
text-align:center;
font-weight:bold;
font-size: 2em;}
h1,h2,h3,h4,h5{margin:0 0 0.25em;}
h2 { font: italic bold; font-size: .75em}
body,html{padding:0;margin:0;}
</style>
<div class="container">
<br /><br /><br />
<div style="display:block; margin-top: 220px;"><h2>{{student_name}} on {{completion_date}} in GEAPS 524: Grain Drying</h2>
</div>
</div>