Short answer: There really aren’t many differences between ORACAL 631 and MACtac 8900. They’re more similar than they are different. Both have a nice matte finish and removable acrylic adhesive. The MACtac is marginally thinner (2.8 mil versus 3mil for the 631) but you won’t really notice that.
The only difference that we have found in our testing that you will notice is that the MACtac is much easier to remove from the liner.
ORACAL vinyls are all a little difficult to get off the liner after they’ve been cut, weeded, and covered with transfer tape. So much so that there are special tips designed to make that easier including the “ORACAL Flip tip” blog post which you can read about here.
In our experience, this is not a problem with the MACtac. It comes off the liner quite easily. This makes it a little easier to use for entrepreneurs who are selling do-it-yourself wall words graphics that are shipped with the transfer tape applied.
The other difference pertains to transfer tape.
Many of our customers prefer a transparent tape to standard paper tapes. The Main Tape Preview Plus medium tack clear tape, which was developed especially for use with these vinyls and wall words, actually works a little better with ORACAL 631 than it does with MACtac 8900. The difference is in that it’s much easier to get the vinyl to stick to the wall when the tape is removed, even on rough or textured surfaces.
When you’re using MACtac 8900, the Preview Plus doesn’t really help on these challenging surfaces and you may have to finesse the tape off to get the vinyl to stick. With ORACAL 631, this tape allows you to remove it after applying the vinyl to the wall with less effort. For more about that, please visit our MAIN Preview Plus blog post.
To sum it up, MACtac 8900 is easier to remove from the liner, but ORACAL 631 is easier to use with clear tape. I hope that answers your questions.