How do you make a seamless Instagram carousel post on Designer?

[northwhitespecs]

Hi all, I've already put all my artboards side by side and moved them as close to each other as possible without overlapping, ensuring that all are aligned. The content is duplicated across the artboards and look fine on the app. When I finally export and upload to Instagram, there's still a single pixel line showing the separation of each image.  

Am I missing something? I've tried arranging them into 0 px between artboards but the option clickable when I open the alignment box, so I'm guessing there's a miniscule gap that my computer is picking up. Any advice would be highly appreciated.

[NotMyFault]

Use the move tool to check the position and size of the artboards.

all must be perfectly integer, no fractional digits.

next, check that all objects inside do the same, specifically those inferring with the artboard edges.

For background, see

 

[Alfred]

2 hours ago, northwhitespecs said:

but the option clickable

It looks as though you may have missed out one or more words here. Which option is (or isn’t) clickable?

2 hours ago, northwhitespecs said:

I'm guessing there's a miniscule gap

<pedantry>
You mean minuscule, not miniscule.
</pedantry>

[thomaso]

7 hours ago, northwhitespecs said:

The content is duplicated across the artboards

I don't know anything about Instagram carousels, but to create multiple artboards with different details of the same content, you can alternatively deselect "Edit All Layers" -> place all content above the artboard layers (which may remain blank) -> export as PDF with "Whole document" -> then get/pick the individual images from the exported PDF. Also, in this case, the edge artifacts don't seem to appear with decimal, not integer object coordinates in AD.

[lepr]

2 hours ago, Alfred said:

<pedantry>
You mean minuscule, not miniscule.
</pedantry>

<off topic> The OED considers miniscule to be an acceptable modern spelling of the word. </off topic>

[Alfred]

6 minutes ago, lepr said:

<off topic> The OED considers miniscule to be an acceptable modern spelling of the word. </off topic>

<off-topic>Like most (all?) dictionaries, the OED can sometimes be descriptive rather than prescriptive.</off-topic>

[lepr]

12 minutes ago, Alfred said:

<off-topic>Like most (all?) dictionaries, the OED can sometimes be descriptive rather than prescriptive.</off-topic>

Sorry for providing information and spoiling your pedantry. 
I did not suggest the OED recommends the newer spelling over the older. 

[northwhitespecs]

4 hours ago, Alfred said:

It looks as though you may have missed out one or more words here. Which option is (or isn’t) clickable?

* is not

Thank you for catching that.

For those who are unfamiliar with Instagram carousels, this is how the exported images come up. Seamless images in this carousel contribute to a sophisticated looking post, and this particular set is supposed to promote a marketing event.