Customised free text box on select products

[EMitchell]

Hi All - total newbie here. 

I'm trying to add a product customisation box to my paperback books. So far I've managed to successfully add the box in but it's showing on all the product pages. I want it to only show on certain product pages - such as those where I'm signing the books. 
Could anyone assist, please? I'm using the Impulse theme. 

www.EvieMitchell.com 

[PaulNewton]

Use alternate templates assign to just those products one by one or using the bulk editor.

https://help.shopify.com/en/manual/online-store/themes/os20/theme-structure/templates#create-a-new-t... 

Otherwise depending on how your doing this use liquid logic with some condition to target only those books such as a tag "signed"

{% if product.tags contain "signed %}

{% endif %}

If you need this customization setup for you then contact me by mail for services, contact Info in signature.
Please always provide context, examples: store url, theme name, post url(s) , or any further detail.