prEN ISO 19076

Leather - Measurement of leather surface - Electronic techniques (ISO/DIS 19076:2022)

ISO 19076:2016 provides a method for the measurement of the surface of leather or leather parts by the use of electronic measuring machines.
It applies to the measurement of leather (or leather parts) fulfilling the following requirements:
-      flexible leather, finished or unfinished, dry or wet leather;
-      flexibility: such to allow full distension on the measuring line/surface.

Leder – Messung der Oberfläche des Leders – Elektronische Verfahren (ISO/DIS 19076:2022)

Diese Internationale Norm legt eine Methode für die Messung der Oberfläche von Leder oder von Lederteilen durch die Anwendung elektronischer Messmaschinen fest.
Die Norm gilt für die Messung von Leder (oder Lederteilen), das (oder die) die folgenden Anforderungen erfüllt (erfüllen):
   flexibles Leder, mit oder ohne Zurichtung, trockenes oder nasses Leder ;
   Flexibilität: um die volle Ausdehnung auf der Messlinie/Oberfläche zu ermöglichen.
ANMERKUNG    Die beteiligten Seiten stimmen sich bei gegerbtem und abgewelktem, nassem Leder über die Art der Konditionierung ab. Im Streitfall wird das Leder nach den Referenzstandardbedingungen in ISO 2419 konditioniert.

Cuir - Mesurage de la surface du cuir - Techniques électroniques (ISO/DIS 19076:2022)

L'ISO 19076 :2016 fournit une méthode pour le mesurage de la surface du cuir ou de pièces de cuir au moyen d'appareils de mesure électroniques.
Elle s'applique au mesurage du cuir (ou de pièces de cuir) satisfaisant aux exigences suivantes:
-      cuir souple, fini ou non fini, cuir humide ou sec;
-      souplesse: cuir pouvant être complètement distendu sur la ligne/surface de mesurage.

Usnje - Merjenje usnjene površine - Elektronske tehnike (ISO/DIS 19076:2022)

General Information

• Status: Not Published
• ICS: 59.140.30 - Leather and furs
• Technical Committee: CEN/TC 289 - Leather
• Current Stage: 4599 - Dispatch of FV draft to CMC - Finalization for Vote
• Due Date: 28-Sep-2022
• Completion Date: 28-Sep-2022
• Ref Project: oSIST prEN ISO 19076:2022 - Leather - Measurement of leather surface - Electronic techniques (ISO/DIS 19076:2022)

RELATIONS

• Revised: EN ISO 19076:2016 - Leather - Measurement of leather surface - Using electronic techniques (ISO 19076:2016)
• Effective Date: 29-Dec-2021

Standards Content (sample)

SLOVENSKI STANDARD
oSIST prEN ISO 19076:2022
01-april-2022
Usnje - Merjenje usnjene površine - Elektronske tehnike (ISO/DIS 19076:2022)

Leather - Measurement of leather surface - Electronic techniques (ISO/DIS 19076:2022)

Leder - Messung der Oberfläche des Leders - Elektronische Verfahren (ISO/DIS
19076:2022)

Cuir - Mesurage de la surface du cuir - Techniques électroniques (ISO/DIS 19076:2022)

Ta slovenski standard je istoveten z: prEN ISO 19076
ICS:
59.140.30 Usnje in krzno Leather and furs
oSIST prEN ISO 19076:2022 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 19076:2022
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oSIST prEN ISO 19076:2022
DRAFT INTERNATIONAL STANDARD
ISO/DIS 19076
IULTCS
IUP 58
IULTCS Secretariat: ISO
Voting begins on: Voting terminates on:
2022-02-23 2022-05-18
Leather — Measurement of leather surface — Electronic
techniques
ICS: 59.140.30
This document is circulated as received from the committee secretariat.
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
ISO/CEN PARALLEL PROCESSING
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference numbers
NATIONAL REGULATIONS.
ISO/DIS 19076:2022(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
IULTCS/IUP 58:2022(E)
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. © ISO 2022
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oSIST prEN ISO 19076:2022
ISO/DIS 19076:2022(E)
IULTCS/IUP 58:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on

the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below

or ISO’s member body in the country of the requester.
ISO copyright office
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Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
© ISO 2022 – All rights reserved
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oSIST prEN ISO 19076:2022
ISO/DIS 19076:2022(E)
IULTCS/IUP 58:2022(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction .................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ..................................................................................................................................................................................... 1

3 Terms and definitions .................................................................................................................................................................................... 1

4 Principle ........................................................................................................................................................................................................................ 2

5 Apparatus and materials ............................................................................................................................................................................2

5.1 Measuring machines.......................................................................................................................................................................... 2

5.1.1 Measuring machines type with linear sensor array (Type A, B, and C) ........................... 2

5.1.2 Type A roller measuring machine ....................................................................................................................... 3

5.1.3 Roller measuring machine with transport roller (Type A1) ....................................................... 3

5.1.4 Roller measuring machine with transport conveyor (Type A2) ............................................. 3

5.1.5 Conveyor measuring machine (Type B) .................. ....................................................................................... 4

5.1.6 Standard conveyor measuring machine (Type B1) ............................................................................. 4

5.1.7 Vacuum tape conveyor measuring machine (Type B2) ................................................................... 4

5.1.8 Flatbed scanning machines (Type C) ............................................................................................................... 4

5.1.9 Camera measuring machine (Type D) ............................................................................................................. 5

5.2 Reference calibrated templates for machine verification ................................................................................ 5

6 Sampling and conditioning ....................................................................................................................................................................... 5

7 General measurement criteria .............................................................................................................................................................6

7.1 General requirement ......................................................................................................................................................................... 6

7.2 Leather orientation during measurement ..................................................................................................................... 6

7.2.1 General ........................................................................................................................................................................................ 6

7.2.2 Measuring whole leathers .......................................................................................................................................... 6

7.2.3 Measuring half leathers ............................................................................................................................................... 6

7.2.4 Measuring leather cut pieces ................................................................................................................................... 6

7.3 Measurement operations .............................................................................................................................................................. 7

7.3.1 Roller machines ................................................................................................................................................................... 7

7.3.2 Conveyor machines .......................................................................................................................................................... 7

7.3.3 Flatbed scanner machines and bi-dimensional static measuring devices...................... 8

8 Measurement procedure ............................................................................................................................................................................. 8

9 Calculation and expression of results ........................................................................................................................................... 9

10 Test report .................................................................................................................................................................................................................. 9

Annex A (normative) Calibrated templates for the verification of electronic measuring

machines ....................................................................................................................................................................................................................11

Annex B (normative) Procedure for the verification of a measuring machine by calibrated

templates ...................................................................................................................................................................................................................13

Annex C (normative) Laboratory record of calibrated templates .....................................................................................15

Annex D (informative) Repeatability and reproducibility ........................................................................................................16

Annex E (informative) Pickled and wet leather conditioning before testing ........................................................18

Bibliography .............................................................................................................................................................................................................................19

iii
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oSIST prEN ISO 19076:2022
ISO/DIS 19076:2022(E)
IULTCS/IUP 58:2022(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www.iso.org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to

the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see

www.iso.org/iso/foreword.html.

This document was prepared by the Fastness Test Commission of the International Union of Leather

Technologists and Chemists Societies (IUF Commission, IULTCS) in collaboration with the European

Committee for Standardization (CEN) Technical Committee CEN/TC 289, Leather, the secretariat of

which is held by UNI, in accordance with the agreement on technical co-operation between ISO and CEN

(Vienna Agreement).

IULTCS, originally formed in 1897, is a world-wide organization of professional leather societies to

further the advancement of leather science and technology. IULTCS has three Commissions, which

are responsible for establishing international methods for the sampling and testing of leather. ISO

recognizes IULTCS as an international standardizing body for the preparation of test methods for

leather.

This second edition cancels and replaces the first edition (ISO 19076:2016), which has been technically

revised as follows:

— the Scope and clauses 3, 4, 5, 6, 7, 8, 9 and Annex A have been editorially and technically modified;

— a new Annex E for pickled and wet leather conditioning before testing has been inserted.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www.iso.org/members.html.
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oSIST prEN ISO 19076:2022
ISO/DIS 19076:2022(E)
IULTCS/IUP 58:2022(E)
Introduction

Leather surface measuring equipment used within the European Union (EU) for legal metrology

applications are also subject to the EU Directive 2014/32/EU “on the harmonisation of the laws of the

[1]

Member States relating to the making available on the market of measuring instruments (recast)” , on

measuring instruments.
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oSIST prEN ISO 19076:2022
ISO/DIS 19076:2022(E)
DRAFT INTERNATIONAL STANDARD
IULTCS/IUP 58:2022(E)
Leather — Measurement of leather surface — Electronic
techniques
1 Scope

This International Standard provides a method for the measurement of the surface of leather or leather

parts by the use of electronic measuring machines.

It applies to the measurement of leather (or leather parts) fulfilling the following requirements:

— flexible leather, finished or unfinished dry leather;
— flexible wet leathers (Annex E);
— flexibility: such to allow full distension on the measuring line/surface.
2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and are

indispensable for its application. For dated references, only the edition cited applies. For undated

references, the latest edition of the referenced document (including any amendments) applies.

ISO 2419, Leather — Physical and mechanical tests — Sample preparation and conditioning

EN 15987, Leather — Terminology — Key definitions for the leather trade
3 Terms and definitions

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/

For the purposes of this document, the terms and definitions given in EN 15987 and the following apply.

3.1
longitudinal advancement sensing system

in measuring machines type with linear sensor array a feeding movement sensing system to detect the

longitudinal advancement of the leather with respect to the linear sensor array
3.2
measuring line

in measuring machines type with linear sensor array is the physical line where the leather presence is

detected by the sensor array
3.3
relative feed

in non-static measuring machines movement of relative translation between leather and the system

detecting its presence
3.4
Testing

operations of setting and assessment of metrological compliance of the device (calibration)

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oSIST prEN ISO 19076:2022
ISO/DIS 19076:2022(E)
IULTCS/IUP 58:2022(E)
4 Principle

The leather surface is measured by means of a measuring system provided with a linear or a

two-dimensional array of uniformly-spaced opto-electronic sensors capable to detect leather presence.

There are two operating principles of sensors: the first based on the presence of an object between the

beam of a source and a receiver, the second based on the image captured by a digital camera.

In both cases the digital data signals are processed by a computer to generate elementary surface

units that contribute to calculate the surface of the sample. The calculation can be displayed, saved or

printed. The leather surface measure is displayed in metric units, having a scale interval of 1 dm . For

testing purpose, a scale interval shall be at least of 0,1 dm . For other unit of measurement, a suitable

conversion factor shall be used.
5 Apparatus and materials
5.1 Measuring machines

The measuring machines are currently built and classified in some basic types, in relation to the

different solutions adopted for the sensor array and for the relative feed.
Measuring machines types with linear sensor array:

— Type A Roller measuring machines: with transport roller (Type A1) and with transport con-

veyor (Type A2),

— Type B Conveyor measuring machines: standard conveyor machine (Type B1) and vacuum

conveyor machine (Type B2),
— Type C Flatbed scanning machines
Measuring machines types with two-dimensional sensor array:
— Type D Type D
5.1.1 Measuring machines type with linear sensor array (Type A, B, and C)
These measuring machines consists at least of:
— a base frame;
— a relative feed-system between leather and measuring system;

— a set of sensors (sensor array) uniformly spaced along a direction normal to the feeding movement,

to detect leather presence;
— a longitudinal advancement sensing system;

— a numerical indicator (display) of the leather surface measure, in metric units, having a scale interval

2 2
of 1 dm . For testing purpose, a scale interval shall be at least of 0,1 dm .

As an option, the machine may be equipped with a stamping or printing system to record the surface

measured value onto leather or onto a label or paper. The distance i between two adjacent sensors for

the detection of leather presence shall not be greater than 27 mm across the feeding direction.

The length of the measuring line defines the detecting width of the machine and shall be indicated in

the test report.

The distance i between two adjacent detection points of the measuring line shall not be greater than

25+1 (27) mm and shall be uniform on all the declared useful working (detecting) width of the machine.

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oSIST prEN ISO 19076:2022
ISO/DIS 19076:2022(E)
IULTCS/IUP 58:2022(E)

Let p be the step of the leather presence detection along the feeding direction: the values of i and p shall

be such that their product i × p is not greater than 1/400 of the minimum measurable surface.

The feeding speed shall allow leather to spread out adequately during measurement. If necessary, the

machine is equipped with a feeding speed adjustment device to aid the fulfilment of this condition.

5.1.2 Type A roller measuring machine

In this type of machine there is a coincidence between the elements that make up the feeding system

and the optical detection system.

A horizontal introduction bench is present before the feeding system to facilitate the hide feeding of the

machine by the operator, and the feeding system is composed by two main sections, one section above

and one section below the introduction plane.

The section above is composed by one set of transparent free running rollers of equal width, each one

including a sub-array of opto-electronic devices (emitters or sensors) and one encoder that detect the

roller rotation, giving the roller the independent ability to detect the longitudinal advancement of the

leather for the underlying portion; all the encoders of all the measuring rollers make up the longitudinal

advancement sensing system.

The section below is composed by one transport system that incorporates one array of uniformly

spaced opto-electronic devices (sensors or emitters), working in axis with the opto-electronic devices

inside the above measuring rollers and making up with them the optical detection system.

The points where the two sections come into contact locate the measuring line of the machine.

5.1.3 Roller measuring machine with transport roller (Type A1)

In this type of measuring machine the transport system consist of one motorized roller that incorporates

the opto-electronic devices that define the measuring line and the introduction bench is placed just

before the measuring line. This means that the sensor array is incorporated into the feeding system,

being the set of free-rotating measuring rollers also part of the feeding system itself.

Once the hide has been inserted between the measuring rollers and the transport system, the same

continues (autonomously) as a result of the friction generated by the light pressure of the rollers on the

hide (skin, leather). The feeding speed can affect the spread out of the leather.

The movement of leathers under the rollers is controlled by their (relative) encoders that are

independent from each other.

During the feeding, leathers can be spread laterally (perpendicularly to feeding direction), slowed

down or stopped on the introduction bench by the operator.

If the machine allows temporary feeding stop during measurement (e.g. by manual holding), this shall

not significantly alter the measuring value.

Any feeding inversion, even partial and/or temporary, shall automatically cancel the measure, unless

the measuring system allows for the inversion in the area calculation. Such information shall be checked

in the instruction manual provided by the machine manufacturer.
5.1.4 Roller measuring machine with transport conveyor (Type A2)

In this type of measuring machine the introduction bench consist of a transport conveyor with

(transparent) belts that incorporates the opto-electronic sensors and that define the measuring line.

This machine is generally used for measurement of area before or after mechanical operations (e.g.

roller press) in the tanning process. It shall not be used for the verification of surface between seller

and customer.
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oSIST prEN ISO 19076:2022
ISO/DIS 19076:2022(E)
IULTCS/IUP 58:2022(E)

The functional description of the device is the same as Type A1. In comparison with transport roller

devices, the conveyor transport minimizes the dragging effect of the leather but could cause a lower

spreading of leather in the edges.
Also in this case, the feeding speed can affect the spread out of the leather.
5.1.5 Conveyor measuring machine (Type B)

In this type of machine the feeding system is independent (separated) from the (linear) sensor array

and no mechanical work is applied on leather during the transport.

The linear sensor array generally consists of an optical detecting bar and a light source bar; the two

bars generally work in transmissive-receptive way but, under certain conditions, reflective is also

possible.

The transport system consists of a conveyor tape that carries the leather through the measuring line

by means of cords or belts without any interference with the optical detection system (for example, by

nylon cords, transparent belts, strip belts).

The detection of leather in the direction of feeding is generally unique for the whole measurement

width of the machine and it is obtained with suitable devices (for example, an encoder applied directly

on a moving part of transport system).

If a service stop is applied, it will be possible to stop the conveyor any time during the measurement,

without affecting the final result. The measurement shall vary if the operator applies a lateral movement

or blocks manually the transport of leather under the sensors.
The feeding speed can affect the spread out of the leather.
5.1.6 Standard conveyor measuring machine (Type B1)

The length of the tape conveyor is adequate to ensure stable support of the leather during the

measurement.

Once most of the leather is laid flat on the conveyor tape, it advances to the measuring line jointly to the

conveyor tape and without any contact with the optical bar. The measurement occurs during the time

that the hide is passing over the measuring line.
5.1.7 Vacuum tape conveyor measuring machine (Type B2)

Similar to type B1 machine but equipped with a low pressure conveyor achieved with an air aspiration

system that keeps the leather more adherent and firm on the transport belt and that partially flattens

eventual wrinkles over the tape conveyor.

Once the hide is laid flat on the first part of the vacuum conveyor, the hide moves through towards the

measuring line attached on the belts.
The air aspiration system can affect the spread out of leathers.
5.1.8 Flatbed scanning machines (Type C)

This type of machine consists of a horizontal surface (flatbed), made with transparent glass, where

leather is laid flat, and a “portal-shaped” frame containing the sensors; the frame is manually or

mechanically moved, over and parallel to the flatbed.

The optical detection system consists of a couple of optical bars: one over and one below the flatbed. An

encoder is also installed to read the movement of the carriage across the flatbed.

The process of measurement is the same of the conveyor machines, but in this case the sensor system

moves while the leather is still on the flatbed.
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oSIST prEN ISO 19076:2022
ISO/DIS 19076:2022(E)
IULTCS/IUP 58:2022(E)
5.1.9 Camera measuring machine (Type D)
The measuring machine consists at least of:
— a base frame;

— a plane surface to spread and support leather, or alternatively, a belt conveyor that stop when the

hide is under the area camera field;
— an area camera with its optical axis normal to the leather surface;
— a system for image processing and leather surface calculation.

Area measuring devices are often inserted in automatic cutting systems and not generally used by

tanneries for selling. Devices are equipped with an air aspiration system that allows the spreading of

leathers and flattens eventual wrinkles over the plane surface. The air aspiration system can affect the

spread out of leathers.

These devices shall not be used for the verification of surface area between seller and customer.

In this kind of devices colour difference between leather and the surface is fundamental for a suitable

identification of the edge of the material and so for the measurement result. Take sure that there is the

more contrast possible between the leather colour and the colour of the plane, or the conveyor, where

the hide is spread. If leather colour does not allow a correct identification of edges, a flat support with a

colour in contrast with leather should be placed below.

For leather with long hair that protrudes from over the edges the results can be affected by the presence

of hairs. So, these devices are not suitable for measurement of area of this leather type.

The leather surface corresponding to the elementary area measuring unit (pixel) shall not be greater

than 1/400 of the minimum measured surface.

EXAMPLE If the image capturing system is able to transfer a (2 m × 2 m) area into a (512 × 512) pixels array,

the surface corresponding to 1 pixel (elementary area) is:
(2 m/512) × (2 m/512) = 0,15 cm
The minimum measurable surface is therefore:
2 2 2
400 × 0,15 cm = 60 cm = 0,60 dm .

Type D devices may be equipped with an air aspiration system that allows the spreading of leathers and

flattens eventual wrinkles over the plane surface. The air aspiration system can affect the spread out of

leathers and consequently the uncertainty of measure. So, its use shall be indicated in the test report.

5.2 Reference calibrated templates for machine verification

Calibrated templates complying with Annex A requirements, such that the area of the calibrated

template is not less than 50 % of the area of the measured leather, or 1,4 m , whichever is smaller. For

bigger leathers 50 % percent of area could be too large. So, in these cases the maximum template area

is 1,4 m .
6 Sampling and conditioning

6.1 Each leather piece making up the sample from the batch shall be identified and labelled. In case

of third party area checking, the minimum number of leathers from the batch is: 12 for leathers up to

150 dm and 6 for larger leathers, unless there is a different agreement between the parties. The value

to be compared shall be the total area of the batch sample and not the individual values.

6.2 For dry leather, spread out or hang leathers in a standard atmosphere according to ISO 2419, so

that air may freely flow on both leather sides; whenever possible use continuous and fast air circulation.

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oSIST prEN ISO 19076:2022
ISO/DIS 19076:2022(E)
IULTCS/IUP 58:2022(E)

The minimum duration of conditioning is 24 hours. It is allowed the stacking of leathers on top of

each other. In this case the duration of conditioning shall be 48 hours and the total number of stacked

leathers shall be a maximum of 6 for smaller leathers and 3 for larger leathers.

In case of haired leather, care is needed to avoid hair protruding over the leather edge, since with

these types of machine
...