By default, Shopify packing slips will not show you custom options for each line item. The following will help you show custom options on your packing slips.

1. Navigate to the store’s Shopify Settings and click on Shipping and delivery.
   
   
   
   
2. Locate the Packing Slip template and click on Edit template. 
   
   
   
3. Locate the following code snippet.

{% if line_item.sku != blank %}
    <span class="line-item-description-line">
         {{ line_item.sku }}
     </span>
{% endif %}
<PASTE CODE HERE>

4. Underneath the code snippet above, paste the following code.

{% for p in line_item.properties %}
{% assign hidden_property = p.first | first | replace: '_', true %}
{% unless p.last == blank %}
{% if hidden_property == 'true' %}
{% else %}
{{ p.first }}:
{% if p.last contains '/uploads/' or p.last contains '/assets/' or p.last contains '/products/' %}<img style="width:50px;height:auto" src="{{ p.last }}"/>{% else %}{{ p.last | newline_to_br }}
{% endif %}  
<br> 
{% endif %}
{% endunless %}
{% endfor %}