Response, print of letter, keycap trimming, soft key, tilt legs, cable, color, packing are eight ways to judge a keyboard's qualtity. 

Response

Keyboard response should be the primary factor in judging the quality of a keyboard. Typing will be so tiring and annoying if the keyboard response is so low. For most of the wired keyboard, response will not be slow. Response latency could sometimes happen in a wireless keyboard.

Print of letter

Letter should be clear for a keyboard. It won’t be user friendly if the letters is not clear. That is why some keyboard has bold letters to enhance its readability.

Commonly there are two types of letter prints technology. Silk print and laser etched. Silk print is the most common letter print in keyboard, especially for those with scissor keys. Silk print is now usually with UV coating to make it inerasable. Laser etched letters are usually used in backlit keyboard or bamboo keyboard.

Both print technology can make the letters clear to see for a long time. But if you require higher, laser etched letter may be your choice.

Keycaps trimming

Keycaps trimming is very important for a keyboard. No matter the keycaps is made by ABS injection or handicraft, the edge of a keycaps should be trimmed well and with no burrs on. Burrs on keycaps edge may cause stuck keys. When this happens, the rubber dome will not able to bounce the keycaps and thus the letter on that keycaps will continue inputting the same letter all the time.

Keycap trimming is especially important for a bamboo keycap. If not properly handled, bamboo blurs on its edge may wound your fingers

Hard keys or soft keys

There is slot for a key stand (or key feet). Slot is used to hold the key stand, meanwhile causes friction. When the friction is too large, a key will be hard to press on. That is so called the “hard key”.

Hard keys are caused mainly by two reasons. One is lacked of lubricating oil. T he other reason is molding problem. In that case, the molding for key slot needs to be remodeled.

Tilt legs

Unfolding the two tilt legs, type on the keys and check if the keyboard is stable while typing. For some bad keyboards, keyboard shakes when you type with tilt legs unfolded. Also check typing when the tilt legs are folded, to see if the bottom stamps work properly. Make sure the keyboard is stable when you are typing with the tilt legs unfolded. 

Cable

Make sure that the cable for keyboard is not too weak to sustain any stretching. Check the diameter of cable. Usually the larger diameter, the better quality it will be. Also check if the plug is gold-plated. Some good keyboard will have gold plated plug.

Color

A high quality keyboard should have good color. You can judge a keyboard supplier or manufacturer’s ability by its skill and craft to handle colors.

Packing

Good keyboard should have nice packing too. Inner package like plastic bag or bubble bag can protect keyboards. Most keyboards that have piano paint will also add a sheet of transparent plastic sheet for protection. Piano paint is easy to get dirty and with finger print on.

Check if the outer cardboard has a good resistance to pressure. Make sure inner and outer packing is well done before you buy a keyboard.