Question: I sometimes receive wedding invitations with pesukim written on them. Can I throw them away or do I need to put them in sheimos?
Answer: The Gemara (Shabbos 115b) writes that if one writes berachos unnecessarily it is as if they burnt the Torah, as they will eventually cause them to be discarded and mistreated. Thus, Rambam (Teshuvos Harambam 268) and the Shulchan Aruch (OC 283:4) writes that one should not write pesukim on a tallis. The Shach (OC 283:6) explains that when the tallis wears out, it will likely be thrown away, together with the pesukim on it.
Following a machlokes in the Gemara (Gittin 6b), Rambam (Sefer Torah 7:14) and Shulchan Aruch (YD 283:3) disagree on whether one may write 3 or 4 words on a document without it becoming holy. The Tashbetz (2) writes that this doesn’t apply if the words are rearranged or not aligned on one straight line.
R’ Moshe Feinstein (Igros Moshe YD 2:135) writes that he didn’t print any pesukim on his own children’s invitations and advises others not to, either. Elsewhere (YD 4:38:4) he writes that while one does avoid the problem if they split the words onto different lines, one should still avoid writing pesukim. R’ Shlomo Zalman Auerbach (Halichos Shlomo, Tefilla 20:n72) likewise disapproved of printing pesukim on invitations, saying that if it contains a full passuk, it requires geniza (burying).
In conclusion, one printing invitations should ideally avoid printing any pesukim on them. If one received an invitation, one should double wrap it in a plastic bag before disposing of it (See Teshuvos Vehanhagos 1:554).