Use spritesheets to reduce time spent sending PNG assets by 90+%

code/modules/research/designs.dm

@@ -51,8 +51,9 @@ other types of metals and chemistry for reagents).
 	return ..()
 
 /datum/design/proc/icon_html(client/user)
-	send_asset(user, "design_[id].png", FALSE)
-	return "<img class='icon' src=\"design_[id].png\">"
+	var/datum/asset/spritesheet/sheet = get_asset_datum(/datum/asset/spritesheet/research_designs)
+	sheet.send(user)
+	return sheet.icon_tag(id)
 
 ////////////////////////////////////////
 //Disks for transporting design datums//