Issue Making Wall Stickers Snap Together

Hi everyone, 

I'm having a bit of trouble with creating some wall stickers - I'm sure there's something super simple and obvious that I'm missing, I'm just not sure what. 

Basically, I'm trying to make some kitchen tile backsplashes that can be placed over the top of wallpaper etc. I've been using a base game wall sticker as a 'base' for the package, as I wasn't sure what other kind of object would work.

I've been able to make the backsplash 'stickers' with the correct swatches and sizes, but my problem is that I've no idea how to make them 'snap' together. 

This is how I'd like the stickers to snap together, which I had to achieve using bb.moveobjects and manually dragging them around before placing.

imgur.com/VmCr6ol



However, without using cheats and having to carefully place them, the tiles instead have large gaps between them.

imgur.com/SERcOwG
imgur.com/xpnw1J3





Or, if I try to bring them closer, they overlap instead.

imgur.com/nxRCNon




I don't know if I'm missing something that's obvious, or if I should have used something other than a wall sticker as a base. I'm so sorry if my explanation hasn't made any sense, I wasn't sure how else to phrase it. 

Thanks in advance!