1.
are you using the text tool? this is the best option because it continuosly rasterises.. meaning that you can scale above 100% without getting “jaggies” as long as you haven’t pre-composed it.
If you are using the text effect, and applying it to a solid, then it doesn’t continuosly rasterise… meaning that if you scale above 100% you will get the “jaggies”
If you are importing text in as bitmaps (ie from photoshop) then the same deal applies, You can’t scale above 100%.
Did that make sense?
2.
You want to use alpha mattes (or luma mattes) to do this. Have a text layer, then below have the texture you want in the text. Then on the lower layer, select “Alpha Matte” from the modes section. Check out the attached picture and it’ll all make sense….. notice also how the text is scaled above 100% but is still crisp…. this is because I used the text tool.`
https://www.bearcage.dreamhosters.com/duff/TRK_MAT.jpg