Should I give my honest to God opinion or just keep quiet?

What is the point of a wedding? If it’s to put on a big show of good taste then go ahead and advise away, assuming your taste is superior.
If it’s to celebrate the love and commitment of two people, then who gives a shit about whether wax seals or bright flowers are on the invitations.

Who even remembers what an invite looks like? This is a complete non issue.

Those look absolutely awful. I would question your taste if you think anything like that looks good. Leave your sister to organise her own wedding.

Yes - and if you didn't like the designs offered, showing her something similar-but-better is the way to go.

My best friend came dress shopping with me - she told me the bigger my skirt got, the happier I looked. My other bridesmaid made comments about things like, "you don't want to look like a Christmas wreath" when I showed pics of greenery etc for my hair, wanted me to care about things that I specifically didn't care about (wanted matching accessories for all bridesmaids when I specifically wanted them to dress individually to suit them).

One of them was focused on getting the best version of what I liked, the other was focused on trying to get me to do what she thought was best.

And for all that is holy, don't try to get someone to change a decision they don't care about.

This is the difference the OP is missing.

Oh and I cannot remember what a single wedding invitation looked like. Unremarkable I suppose. The last one I went to was all electronic.

I quite like the design, but then I am divorced so what the hell do I know!

Brilliant idea for if I ever get married. Let my kids write the invites, see if anyone actually manages to decipher them and arrive! 🥳

To be honest you can also get them in the papeteries in Italy that sell handmade Italian paper at exorbitant prices, as well as in the fine stationery departments at both Liberty and Fortnums.

They have their place and their followers. It’s just not for everyone, or indeed for every circumstance.

I think attacking op’s suggestions as naff or passé or tacky or pretentious is just as rude as op thinking her sister’s choice is rubbish.

Why not just let people be. And fwiw - and to reassure those brides who have put effort into their invitations - some people do appreciate them. My mum’s friend keeps them in an album with photos from the weddings of family and friends they are close to. Likewise I was at a friend’s house and remarked that she had a lot of weddings coming up. She said “oh actually three of them are past, I just can’t bring myself to bin the beautiful invitations.”

Of course many people will bin them - but it doesn’t always mean it’s because they didn’t appreciate them on the way through.

And then there’s those who don’t notice, don’t care. We are all different.

@Payets
Genuinely curious, why does it matter once she's happy?

The border you have shown in your example is fine

WTF is it about weddings? Wearing a tiara, hiring a fancy car to drive you to a church that you've seen in the inside of a handful of times? What is it about weddings that has people pretending to be something they're not for the day(s).

We used FILS computer and printer (quite a novelty back then) to print our own. Honestly I don’t think anyone gave a shit. Been married for a very long time. It doesn’t matter.

I think you're the one projecting, far more than others on the thread. It's very arrogant to dismiss everyone else as keyboard warriors taking out their frustrations at friends and family on the OP.

I've never had anybody like the OP in my life and I still think she's being a total knob.

I also find it hard to believe people taking her shopping to get the benefit of her opinions.

Sister showed me her wedding invites and they were truly awful. I shared alternatives. Said they were a little dated. Offered my services re ribbon tying and wax seal applying. But sister was like “who gives a shit”. I can tell she is getting annoyed

At which point, of course you drop it! Not sure why you'd say anything else if it's annoying your sister. While I understand that you are used to offering advice, it should be no more than that. It's her wedding! The only thing you should be saying is 'if you love it, then it's perfect. And for what it's worth, she's not wrong about ribbons and wax seals being a little dated. It's much more on trend at the moment to have single page, unfolded invitation cards, often with a border similar to the picture you posted. I work in the wedding industry, and this type of design is very popular at the moment.

Do I change the habit of a lifetime and allow her to make shit choices??

Can't you just accept that your sister has different taste to you? It doesn't make her choice shit, just different! And how gracious of you to 'allow' her to make her choice.

Lol, I had one of those seals from Past Times. It was a gift and I thought it was rather grand at the time (I was a teenager!) but charity shopped it a few years later as I realised that I wasn't ever going to use it!!

When your sister asks which you prefer, just give her an answer. No need to get into the finer detail of why, unless asked. DP is a details person. I rarely ask for his opinion because it takes half an hour to listen to it. By the end I just feel more confused and a bit worn out by the level of analysis. I tend to ‘just like’ something. Of course there are reasons, but I don’t need to delve too deeply into them. He does and that’s fine - for him. So, maybe state your preference and leave it there. No need to suggest alternatives or nit pick over her choices. And if she’s a ‘that’ll do’ type person, so what? We can’t all be interested in the why’s and wherefore’s of everything. Perhaps she has things she IS particular about, but they just aren’t the same as yours. Different priorities and all that.

To me, the idea of wax seals is hilariously pretentious

It's the sort of thing you used to get in the now defunct Past Times shops selling faux vintage and historic tat.

I think her invites look more fun.

This sort of thing is so overdone.

In my opinion, the border is hideous but then I also think wax seals and ribbons are very dated - it’s simply down to personal taste. Let her do as she wishes and leave it.

Sounds to me like you are used to being held in high regard for input into furniture and art and design and used to folk following through with your advice.
Honestly, no one cares about the invitations in the grand scheme of things.

op, with respect, you sound horrendous. ive witnessed the dynamics you describe between you and your sister in my close friends and its painful to watch. one sister thinking shes better with better tastes blah blah, and the other sister doubt and second guess herself all the time. just let your sister be herself and enjoy her own choices in life without your need to butt in with your 'superior' ones.

Wax seals are a bit Taskmaster.

Poor Aunty Doris receiving an invite and panicking that she's going to have to launch an aubergine the farthest North she can in 20mins

They aren't shit choices, they are her choices. Frankly I think the wax seal is unbearably pretentious. You seem confident that your style is better, and should be what everyone wants. It isn't, don't be so over bearing.