Hello, [Note: this has been originally observed in GNU Emacs 26.1 running on Debian Buster GNU/Linux, and then reproduced on the latest Emacs snapshot, 28.0.50.] When there is some particular charset property on text, Emacs chooses to render it using font that has matching encoding, such as: x:-xos4-terminus-medium-r-normal--16-160-72-72-c-80-microsoft-cp1251 (#xEF) for windows-1251 charset rather than the default font: ftcrhb:-PfEd-DejaVu Sans Mono-normal-normal-normal-*-15-*-*-*-m-0-iso10646-1 even though the default (unicode) font does support corresponding characters. This behavior results in rather unpleasant mixture of fonts. To reproduce this starting with emacs -Q, evaluate this form: (let ((buf (get-buffer-create "test encodings"))) (with-current-buffer buf (erase-buffer) (insert "Encoding windows-1251: " (propertize "привет\n" 'charset 'windows-1251)) (insert "Encoding unicode: " (propertize "привет\n" 'charset 'unicode))) (switch-to-buffer-other-window buf)) Be warned that it's known not to be reproducible on at least some systems. What I see in "emacs -Q" is attached as Emacs window snapshot. Please notice how two strings look very different where encodings differ. Here are outputs of C-u C-x = being pressed on 2 differing texts: --- >8 --- position: 24 of 60 (38%), column: 23 character: п (displayed as п) (codepoint 1087, #o2077, #x43f) charset: windows-1251 (WINDOWS-1251 (Cyrillic)) code point in charset: 0xEF script: cyrillic syntax: w which means: word category: .:Base, L:Left-to-right (strong), Y:2-byte Cyrillic, c:Chinese, h:Korean, j:Japanese, y:Cyrillic to input: type "C-x 8 RET 43f" or "C-x 8 RET CYRILLIC SMALL LETTER PE" buffer code: #xD0 #xBF file code: #xD0 #xBF (encoded by coding system utf-8-unix) display: by this font (glyph code) x:-xos4-terminus-medium-r-normal--16-160-72-72-c-80-microsoft-cp1251 (#xEF) Character code properties: customize what to show name: CYRILLIC SMALL LETTER PE general-category: Ll (Letter, Lowercase) decomposition: (1087) ('п') There are text properties here: charset windows-1251 --- >8 --- position: 54 of 60 (88%), column: 23 character: п (displayed as п) (codepoint 1087, #o2077, #x43f) charset: unicode (Unicode (ISO10646)) code point in charset: 0x043F script: cyrillic syntax: w which means: word category: .:Base, L:Left-to-right (strong), Y:2-byte Cyrillic, c:Chinese, h:Korean, j:Japanese, y:Cyrillic to input: type "C-x 8 RET 43f" or "C-x 8 RET CYRILLIC SMALL LETTER PE" buffer code: #xD0 #xBF file code: #xD0 #xBF (encoded by coding system utf-8-unix) display: by this font (glyph code) ftcrhb:-PfEd-DejaVu Sans Mono-normal-normal-normal-*-15-*-*-*-m-0-iso10646-1 (#x37E) Character code properties: customize what to show name: CYRILLIC SMALL LETTER PE general-category: Ll (Letter, Lowercase) decomposition: (1087) ('п') There are text properties here: charset unicode --- >8 --- For reference, here is a link to original report/discussion: https://lists.gnu.org/archive/html/help-gnu-emacs/2020-03/msg00049.html In GNU Emacs 28.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.5, cairo version 1.16.0) of 2020-03-08, unofficial emacs-snapshot build: http://emacs.ganneff.de/, git commit 0a3f8da6e1a56ada409cf1677ac40fcc75a8a33c built on runner-19980c3f-project-26-concurrent-0 Repository revision: d01cf197911a365e4422a5561a0cd77fed4d8fc3 Repository branch: HEAD Windowing system distributor 'The X.Org Foundation', version 11.0.12004000 System Description: Debian GNU/Linux 10 (buster) Recent messages: For information about GNU Emacs and the GNU system, type C-h C-a. Defining kbd macro... Keyboard macro defined completion--do-completion: Keyboard macro terminated by a command ringing the bell Quit # Configured using: 'configure --build x86_64-linux-gnu --prefix=/usr --sharedstatedir=/var/lib --libexecdir=/usr/lib --localstatedir=/var/lib --infodir=/usr/share/info --mandir=/usr/share/man --with-pop=yes --enable-locallisppath=/etc/emacs-snapshot:/etc/emacs:/usr/local/share/emacs/28.0.50/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/28.0.50/site-lisp:/usr/share/emacs/site-lisp --build x86_64-linux-gnu --prefix=/usr --sharedstatedir=/var/lib --libexecdir=/usr/lib --localstatedir=/var/lib --infodir=/usr/share/info --mandir=/usr/share/man --with-pop=yes --enable-locallisppath=/etc/emacs-snapshot:/etc/emacs:/usr/local/share/emacs/28.0.50/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/28.0.50/site-lisp:/usr/share/emacs/site-lisp --with-x=yes --with-x-toolkit=gtk3 --with-toolkit-scroll-bars 'CFLAGS=-g -O2 -fdebug-prefix-map=/builds/joerg/emacs/buster_amd64/emacs-snapshot-20200308+emacs-27.0.90-434-g0a3f8da6e1=. -fstack-protector-strong -Wformat -Werror=format-security -Wall -fno-omit-frame-pointer' 'CPPFLAGS=-Wdate-time -D_FORTIFY_SOURCE=2' LDFLAGS=-Wl,-z,relro' Configured features: XPM JPEG TIFF GIF PNG RSVG CAIRO SOUND GPM DBUS GSETTINGS GLIB NOTIFY INOTIFY ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE HARFBUZZ M17N_FLT LIBOTF ZLIB TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM MODULES THREADS PDUMPER LCMS2 GMP Important settings: value of $LC_MONETARY: en_US.UTF-8 value of $LC_NUMERIC: en_US.UTF-8 value of $LC_TIME: en_US.UTF-8 value of $LANG: en_US.UTF-8 locale-coding-system: utf-8-unix Major mode: Fundamental Minor modes in effect: tooltip-mode: t global-eldoc-mode: t electric-indent-mode: t mouse-wheel-mode: t tool-bar-mode: t menu-bar-mode: t file-name-shadow-mode: t global-font-lock-mode: t blink-cursor-mode: t auto-composition-mode: t auto-encryption-mode: t auto-compression-mode: t line-number-mode: t transient-mark-mode: t Load-path shadows: None found. Features: (shadow sort mail-extr emacsbug message rmc puny dired dired-loaddefs format-spec rfc822 mml easymenu mml-sec password-cache epa derived epg epg-config gnus-util rmail rmail-loaddefs text-property-search time-date subr-x seq byte-opt gv bytecomp byte-compile cconv mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils kmacro cl-loaddefs cl-lib tooltip eldoc electric uniquify ediff-hook vc-hooks lisp-float-type mwheel term/x-win x-win term/common-win x-dnd tool-bar dnd fontset image regexp-opt fringe tabulated-list replace newcomment text-mode elisp-mode lisp-mode prog-mode register page tab-bar menu-bar rfn-eshadow isearch timer select scroll-bar mouse jit-lock font-lock syntax facemenu font-core term/tty-colors frame minibuffer cl-generic cham georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms cp51932 hebrew greek romanian slovak czech european ethiopic indian cyrillic chinese composite charscript charprop case-table epa-hook jka-cmpr-hook help simple abbrev obarray cl-preloaded nadvice loaddefs button faces cus-face macroexp files text-properties overlay sha1 md5 base64 format env code-pages mule custom widget hashtable-print-readable backquote threads dbusbind inotify lcms2 dynamic-setting system-font-setting font-render-setting cairo move-toolbar gtk x-toolkit x multi-tty make-network-process emacs) Memory information: ((conses 16 45267 8851) (symbols 48 6071 1) (strings 32 15735 1935) (string-bytes 1 511300) (vectors 16 9543) (vector-slots 8 130234 10600) (floats 8 25 44) (intervals 56 261 6) (buffers 1000 13))